I have lap surgery in a week and a half, and I'm terrified.

I'm 19F, and have a lot of medical trauma and anxiety. This is my first ever surgery surgery besides tonsil removal at 4 and widsom teeth at 16. I had an endoscopy in September that I was treated horribly for. They didn't really tell me much besides the fact that I'll have an IV and it will put me to sleep. The staff member rolled me into the op room and I remember everyone coming in and not saying much to me. I started feeling the anesthesia, could not move or even speak and they start strapping me down and putting this horrible mouth guard in my mouth that strapped around my head. I was searching for someone eyes to make contact with and the next thing I remember is waking up at 6 pm that night in my bed. It was a terrifying experience being so alone and helpless. Anytime I even remotely think about the surgery itself I am so overwhelmed and scared. Thankfully, they are doing an IUD during my surgery. So my fears of the surgery being for nothing and not finding endo are whatever because the surgery isn't for nothing. I was on the pill for 5 years when I first started reporting these symptoms and I became extremely depressed and suicidal and self harmed. I refuse to take another birth control pill again and do and IUD or implant while awake without any pain medication. So the IUD while under relieves so much anxiety for me and for the future. How do I cope with going under? I don't want to be alone and so afraid and want my partner and support person with me, or at least someone talking to me making sure I'm okay. What is recovery like? I'm so scared of the pain of the site and also gas pains I'm terrified of. Constipation is whatever for me as I already am prolifically constipated to begin with and I already have Gas-X and fiber powder to hopefully move things along. I'm extremely self concious of my self image and my body and I don't even want to imagine the scars. I feel so childish for being so terrified and breaking down everytime I think about it. I already have a therapist and medication manager and already have been diagnosed with anxiety, major depression, PTSD, and BPD. I don't want to be a hot mess at the surgery center at 5:30 in the morning. Any advice and help please?