PKU

Is there anyone that was diagnosed with PKU as an adult? Everything I read says it’s possible but extremely rare. I’ve been having issues with daily headaches that make me feel so fatigued and tired, low mood, brain fog etc and after a long process I have worked out that protein is the issue which lead me to PKU. I have been a vegetarian since I was 14 and vegan since I was 37 and haven’t typically consumed a huge amount of protein so I’m wondering if this is why it’s gone undetected. I’ve always suffered with headaches right from a little kid. I also don’t know if you can have flair ups with PKU but in my early 20’s for a number of years I had chronic headaches and mental health issues, chronic fatigue etc and when I think back I was consuming a lot of protein during this time. I’m now in my 40’s and this has again been going on for a number of years and I think it is also linked to increased protein intake. I’m struggling with what to eat because too much protein and the headaches start again but not enough and it really affects my blood sugar and makes me feel generally unwell. I’ve had to stop exercising because I can’t eat enough protein to recover from high intensity work outs and it takes me days to recover I’m so wiped out.