It's completely up to you whether or not you're ready to start a healthier lifestyle. It takes a lot of dedication to want to change your old habits for good, especially when you don't have any support around you (that's what Curezone is here for :D).
Going raw is definitely not easy and may have to be on your top list of priorities to keep. Fresh produce is a must, and it's not always available at work, school, malls, drive-thrus, etc. I always have nuts and a fruit in my purse :). Being a raw-foodist is a major part of my life, and every where I go it's going to be with me. It's not exactly COOL or anything, and not everyone understands it, but I think it's a great lifestyle and anyone who cares about their body can do it.
The best advice you can get, is from your own body. If you think it's best that you go back to eating your regular diet, you should do so. You may have adapted your body to eating a certain diet and think that it's better for you, but this may not be so. Someone can adapt their body to eating 5 HO-HO's for lunch, and eat an apple later and have indigestion. Not because apples are BAD, but because the body may be so low on nutrients to break it down and the organs aren't functioning their best due to malnutrition.
I think you said you were going for 4 days. I'd say that's a pretty good start. Maybe try introducing some steamed fish the next day for dinner with some veggies or some other lean meat. If you want to help get rid of the acids in your body from the cooked meat, try replacing some meals the next day with some lemonade. Juice 1/2 lemon, 1 1/4c water, and 2 tbls. grade b maple syrup (honey and agave nectar are good also). When your ready to try again, set a goal for 2 weeks-month.
It may help if you look into doing other cleanses to get rid of what you may have put into your body after so long, before changing your diet. Try reading the forums on Parasites, Bowel Cleanse, Master Cleanse, and Liver Flushing.
Remember that everyone is different, so what is true for someone else, may not be true for you, so keep listen to your body. Keeping a health journal would be a good idea.
As for losing muscle mass, you will probably only lose the glycogen reserves from your muscle for energy after a while on a raw food diet. I noticed this in myself after about 1 1/2 weeks on a juice fast. To keep the body and muscles strong, you could try doing yoga along with your new diet.
You can always come back and try again if you can't go through with it :)