Are mental disorders real?

I've been seeing a therapist since I was a little girl.
I don't remember much but I do remember them teaching me how to act like other kids or something like that...
Also in kindergarten I remember not having friends and being happy playing by myself,eating by myself.

I stoped seeing my therapist 2 years ago.
I'm making money,enough to save up alot of it so I feel like I'm fine but I know I'm not.
I know there's something wrong with my brain or maybe I'm just naturally fucked up.

Now as an adult when people get to know me they think something wrong with me.

I know I'm a little weird and all that.