I would be offended that your boyfriend would not take your word, like having an illness has anything to do with whether one's thoughts/opinion is trustworthy.

I go to the medical doctor every 3 months and discuss my health, all of it. When he wants me to go to specialists, we discuss it and I decide it is/is not what I want to do. Not going to the doctor because one is afraid of what they may or may not tell you is "magical" thinking; the outcome cannot be affected by pretending a condition does not exist. If all you want in life is to be "functional" then that is one thing but I can't imagine you enjoy harming yourself, dealing with hallucinations, being afraid of the dark? Getting a few experts opinions and ideas on what might be done to help; it does not have to be psychiatric medicine, there is counselling and the condition could be caused by something physically wrong, you can't know that unless you get it checked out?