Hey bella! First thing, about fats: Don't be afraid of them!! I used to avoid fats like the plague at the height of my ED, and because I naively assumed the common myth "fat makes you fat." In short, my gallbladder became very painful and full of stones from lack of use for years (fat consumption stimulates the gallbladder,and thusly mine wasn't stimulated), negatively impacting my digestion. Also, fat is necessary for brain health (your brain is made up of fat, you know!), emotional health (helps to balance hormones), skin and hair health (moisturizing), and it helps to give you physical strength and satisfy hunger (which may be good for your cravings). Oils, raw nuts and seeds are great sources of fat that WON'T make you gain weight.
A bit of raw honey is great for sweet cravings. One thing that may help is learning about portion sizes - I know it did for me. You can start for the first month or so measuring out portion sizes of foods, and sticking to that. Then, once you feel comfortable with what the size of proper portions look like, practice doing it by eye instead (like maybe 1 handful = 1 cup, ect.) It may also help you to keep a food diary to keep track of what you eat. When you're consciously aware of what you're eating, then you may not be as tempted to binge eat. The thing about purging, which you may already know, is that it doesn't really get rid of calories. Your body absorbs the calories right away, when you purge all you really loose is water, so you're putting yourself at great risk of dehydration and imbalanced electrolytes, which can eventually lead to heart problems.
I know for me, educating myself about my ED, the symtoms, the health issues it can lead to, everything, really helped me gain awareness of what I was doing. I think most people with EDs aren't aware of the damage they're doing, not just to their bodies, but to their personal relationships. You may notice you become more withdrawn with an ED and more secretive about food, with me I hated eating in public and going out to restaurants, which made socializing difficult. I've met other people with EDs who have told me if they could go back in time and start all over again, they would never have started the behaviour in the first place. The thing is, it's not too late to turn around. You don't have to go back in time to change you're behaviour. You can start now. All you have to do is start slowly changing your patterns: your behavioural patterns (purging, binging), your mental patterns (obsessing over calories, fat), and your emotional patterns (how you react to stress - binging and purging is a reaction to stress, when you get right down to it is has nothing to do with weight, it has to do with a lack of control in your life). It sounds a lot easier than it actually is, but be GENTLE with yourself. Start one thing at a time. Changing these patterns is how you REALLY get on control of your life - binging and purging is controlling you right now, otherwise you wouldn't be in Curezone looking for help on how to stop it.
The reason I suggested therapy is there is a certain type of therapy called cognitive therapy that you may find beneficial. I know there are certain cognitive therapists that specialize in EDs too. Cognitive therapy is all about changing your patterns and how you react to stress, it's more than just talking out problems like traditional therapy. Another thing you may find helpful is getting more in touch with your body in a spiritual way, like gentle yoga, meditation, and doing other things that give you true enjoyment - maybe painting, singing or writing gives you joy. Make time to do that or join a group/class that revolves around your interest, if you can. If you're into spiritual/new age topics, maybe reading some books on the subject may help you. Personally, there's a book called "You Can Heal Your Life" by Louise L. Hay that helped me a lot - there's a workbook that goes with it. If you can get both the book and workbook, I think you may like it. It's simple and easy to read. Give it a shot if you want, it really did help me.
You're lucky your sister is so supportive :) Maybe having your sister read some stuff about your ED and how to help you may assist her in understanding you right now. If you think it's a good idea, show her this site and this page in particular:
It's a good site for ED sufferers and their families. EDs are very commonly misunderstood, try not to be offended if someone makes a comment about your ED or behaviour, or says something about your ED that makes you uncomfortable. They don't know they're hurting you. The best thing you can do is say, "I'm sorry, but please don't say that. It makes me uncomfortable. I'm doing my best right now and it would mean a lot to me if you could just appreciate that." I know for me my family didn't understand or really care at all, and they always said things like "Why can't you just eat like a normal person?" "You're so skinny, look at you!", even today every time I see my dad he always comments on my weight, but comments in the same breath how he doesn't believe guys like overweight girls. It's just ignorance, do your best to ignore it and concentrate on YOU. Give your loved ones the materials to educate themselves on your ED and condition, and if they're interested, they'll pursue it and help you. If not, then that's they're issue. It's not a reflection on you. If someone wants to help you, don't be afraid to tell them your feelings when you're stressed. I don't know, but it could be that you keep your feelings inside instead of properly expressing them and letting them out, and that's a factor in your ED.
If shopping at places like Trader Joe's and Whole Foods feels "safe" to you (you can keep those foods down and not purge them like fast food/restaurant food), then shop there as much as you can. You will eventually feel more comfortable going outside your comfort or "safe" zone as you heal, but like I said, go as far as you can right now, starting with keeping food down :) The sensation of having food in your stomach and digesting will likely feel uncomfortable and "heavy" at first - that's normal and it will go away with time. Remember everytime you DON'T binge/purge you're really taking control of your life, because you're not doing anything to damage your body. Instead, you're helping you mind and body heal. That's real control.
Take care, bella :) We're happy to have you at Curezone!!