Should I go back to high school?

I am an 18 yo M. My parents more or less forced me to drop out of high school (I homeschooled) at 14 after the 8th grade. I really liked school, and did very well ( I was that nerd on the math team and everything haha). I’ll be turning 19 in August, and I have the opportunity to return to high school and graduate this coming year if I do summer school and work hard. I am worried I’m too old to be in high school, though. I should have graduated this year. I don’t feel old, and I know I’m not, but when I say it out loud, 19 sounds awful old. I’ve read about others in similar situations, some people say it’s just fine, not a big deal, while others think it’s horrible to put 19 year olds in school with 15 year old freshman. They say they’re bad influences and “creeps”. I don’t consider myself a “bad influence”, I wouldn’t step on an ant haha. I have the option of taking the GED, however I am looking to get into a math/physics program in college and admissions tell me they look down on GED’s when your looking into programs like these. They have plenty of kids that have passed AP or IB classes and have real diplomas, and I have a couple relatives that took the GED path and didn’t have much luck. I’ll have the opportunity to take AP or IB math and science classes if I choose to go to this high school, which I think would be great if I’m going to get into something like that. And perhaps most important to me, I’ve never had friends, being homeschooled, and I have a bit of social anxiety and I don’t feel ready to be in a college setting. It gets awfully lonely having no friends to talk to and never gotten the chance to hang out or do stereotypical “teenager stuff” like go to the mall or the arcade or something, or at least have someone to share your thoughts with. I’d love the opportunity to be part of a club or sports team, to get to go to a dance or prom, and have the friendships I’ve missed out on, maybe some people to support me as I transition to college. I just feel weird being as old as I am and considering going back to school. Like I said, I don’t feel almost 19, but when I say it out loud or type it in here it sounds “old”. I can’t believe it’s my last year as a teenager, I flew by so fast and I feel so unprepared to be an adult. I know of one 19 yr old senior at the school now, but he turned 19 only a month or two before the end of school, i’ll Turn 19 just before the year even starts. What do you think? Should I go back? Can I make up for some of the memories I missed out on? I don’t want to grow old and not have any memories to reminisce later on in life either. Thanks so much in advance for your advice.