Does an official diagnosis help

Hi. I have been seeing a therapist for about two and a half years now. We have recently been talking about my possible autism. My therapist has said that although she can't diagnose me, my charatiristics/ things that I struggled with would probably be categorised as autism. I have done research myself  and through speaking with family members, think I am autistic.

Is going through with a proper diagnosis worth the appointment s and stress? I am conflicted, some family members are encouraging me to peruse it, others think it's enough that I know myself and can get help in other ways. 

Did getting a official autism diagnosis help other people?