I had this same problem exactly. My freshman year I was at a big 10 university where everyone and their mothers were pre-med or engineering. I wanted to become a doctor and have the prestige and money to come with it. Like you said, however, the culture of pre med was just awful and at this university it was a fight to the death for every single grade. My family and friends were so supportive of me and had such high expectations that I felt I couldn't admit that I didn't like the idea of spending a large amount of my life in school. I transferred my second year to a smaller university, and there are many more PA students than med at this uni. At that point the decision consumed me as well. I shadowed quite a few PA and MD both, and I ended up choosing PA after many tears, venting sessions to my poor BF, and tons and tons of research.
I am very much like you, scientifically oriented and love explaining medicine to others, but also very introverted. I could take or leave leadership positions as well. PA is a perfect fit for me because I get to have a very consistent job in medicine doing exactly what I want, but I also get to have a little more room for "me" time. Another large factor was that it's only two years versus four, and I am positive I don't want to stay in the same specialty my entire life, so I didn't like the thought of residency. Med school costs more than pa school to begin with (depends on the school of course) and I have to think that those extra years in med school and residency I could've been working as a PA. I have been accepted to a couple pa schools and will be attending in May. I plan on doing the loan repayment programs for NHSC, and there are many more programs like this. I will start in primary care to get the loan repayment and then probably bounce around.
As for the whole ego part of the choice, absolutely no one has said to me "well you'll just be someone's assistant right?" Or anything like that. EVERYONE who knows the profession tells me "that is awesome, i know someone who is a pa and loves it" or tell me about a PA they saw once and they loved them. My shadowing experiences seemed like the PA and docs did almost the same work, and had the same level of respect. This was all in one area of a state, however, so it could just be a local thing.
I am not trying to sway you towards PA, I'm just giving you an honest look at what my experience has been. However, I feel like your post was hinting that you're leaning towards pa, but you don't want to tell your family and friends and be judged. My best advice is get in touch with some MDs and PAs and just talk to them. People love to talk about themselves, right? They'll give you an honest answer. Ive had doctors tell me "don't become an MD" and others that said "you should go to med school". I've never had a pa tell me I should go to med school.
That's my very long two cents and I am sorry about the length. Again, not trying to sway you, just giving you an honest look into my struggle. I am very happy with my choice and excited/nervous to start in May.