The first step is to stop thinking of your self as abnormal. If you are on the spectrum, then you're probably perfectly normal for somebody with an ASD.

I got diagnosed a year ago (at 27) and I'm glad I got diagnosed. I'd spent my entire life wondering why I never fitted in, why I seemed to react differently to most situations than my peers, why I felt I constantly had to explain that I preferred to be on my own than in a group, etc. A life time of thinking you're abnormal or weird does terrible things to your self esteem. I developed other mental health disorders including OCD and DID, along with continuous bouts of deep depression.