Any advice on being assessed for autism?

Hi everyone. I am just here looking for a bit of help. I am 24 years old and have struggled mentally and socially for as long as I can remember. It started with being obsessive as a child. I struggled with s chool and to this day I still struggle to make friends. I find myself not understanding other people and how they feel and just things that other people find easy are hard for me. Things like having a conversation. I hide it really well, but I feel as if I have been hiding it for a long time and it is exhausting. I have outbursts caused by frustration and becoming too overwhelmed. These outbursts have involved anything from head butting or punching things to throwing myself down the stairs. I don't understand why I do this I just feel like I am so overwhelmed by situations and I don't know what to do with the emotions and information I am dealing with. I have now booked a doctors appointment for next week but I was just wondering if anyone is in a similar situation and how others have coped. Particularly with the social side, outbursts and sensory problems. Thank you so much in advance.