Well I am not in the same situation as you but in similar I think. I was diagnosed with PKU at the age of 10 and after turning 18 I had very relaxed diet which I found wasn`t too good for me. I had the same problems as you mentioned. Getting back on diet is very hard especially at the begining with time it gets easier. If you want PM me.
Greets
'Where you live should not decide
Whether you live or whether you die'