I myself started eating a (mostly) raw food diet starting about 3 weeks ago. The only meats I ate were wild fish or grain fed beef. So I'll share what I've experienced thus far. I'm a 26 years old btw.
The first week my digestive system reacted and I had excess gas from not being used to digesting so many sugars and enzymes. I also began breaking out from all the detoxifying I'd been doing.
Starting week 2 I began to feel more energy, a greater clarity of mind, and my skin was looking better, but still had room for improvement. I kept to a basically vegan diet for this entire week, with the exception of 1 or 2 wild salmon filets.
Week 3, I began to cheat more, I remember eating some msg ridden chinese food one night, and the less guilt ridden deli sandwich a couple days later. I did stay in the habit of eating mostly raw though.
I'm beginning week 4. I feel better, my digestive system is working almost perfectly, and I'm normally bursting with energy.
So what would I do differently?
The first week I would have cut my intake by about 25% to avoid excess gas. I would also have drank more water to help take more burden off my skin during detox. I still feel like I'm detoxing but to a far lesser extent since I'm gradually getting healthier.
Wow that seemed long winded. Good luck!
I also wanted to tell you that your metabolism is probably slowing down because of massively lowering your caloric intake, this may be why you are not eliminating with every meal (just a theory). You are also not getting much fat, which is usually why you have to go the the bathroom after you eat greasy food (natural laxative).