well i think that it's cos ur not eating enough considering ur on 43 exchanges ur only eating 10-15 exchanges a day by the looks of things from what u have put on ur comment. Im on 3 exchanges a day and im eating a more varied diet daily than u do!!
Becky is right as well u dont seem 2 be eating a lot of calories and they help a hell of alot!!
I know a pregnant pku on just 24 exchanges thats almost half what u r on and she is eating chicken and eating out in the likes of kfc's, so i couldn't imagine what u could eat!! There is a hel lof lot more foods u could and probably should be eating if ur on that may exchanges.
Im always ere if u wish 2 add me as friend any questions u may want 2 ask i will always reply not that im an expert like but i'd like 2 hope i could help u as much as possible!
Hope 2 hear from u soon and good luck, oh n i would suggest u have ur bloods done 2 see were there at it could be that there very low and ur not gettin enough out of the foods ur eating or if there high it's more than likely what every1 else has said on ere that ur not eating enough calories and not enough variety in ur diet.