How the hell do you go to therapy?

I’m at a point where I know I desperately need it, but at the same time I’m physically incapable of talking about anything other than my work with anyone. Aside from my job and the little social interaction I have to deal with there, I’ve completely isolated myself out of fear/shame/anxiety/whatever.

I’ve been seeing this psychiatrist since I was kid for ADHD, and we call every 3 months for like 15 minutes so I can keep getting those meds. I’ve tried several times to bring it up to him that I think I might have AvPD, but I keep stopping myself because I irrationally feel like he would hate me if he knew how much I wasn’t telling him about the rest of my life and mental health.

For those of you who have actually gotten therapy: how the hell did you do it?