PIP Application Dillema

I have been delaying applying for PIP since I read the guides about mental health earlier this year. My psychologist at the hospital said they would support me with a report and said I should apply. I think I would pehaps get it on the mobility part. I have written down how it affects me and it is the majority of the time etc. What I would like to ask as for example migraines I have 3 a month lasting 2-3 days and this worsens my issues in that I would not go out but would if I did not have the migraine if I had a good day mental health wise. Is it worth mentioning the migraine and any other lesser conditions that do not have a majority of the time on its own? I am doing a diary and it will take time getting the evidence from these minor/majority conditions some of which componding might get sufficient for daily living. I am not sure how long it will take to get some recent evidence if I have to wait to go for tests, in the meantime I am delaying my phone call to them to start the ball rolling but with potential changes by gov next year I am not sure if this is a wise move. If I get PIP for mobility then later I would have to fill out another form and get reassessed when I do get the other evidence for daily living. That is why I am delaying and would like some advice. Thank you