Wow.... you post for help in a terrifying situation and all you get in reply is more posts saying that you shouldn't do it... as if you decision isn't hard enough.
I had an abortion about 11 years ago at about the same stage as you. Mine was at Planned Parenthood, so I'll let you know what my experience was like; yours will likely be similar.
You are given a pill for the pain, as well as a local anesthetic, but the procedure itself does hurt. I had the option to have a nurse hold my hand, which was incredibly helpful. It doesn't last for very long, and you sit in a recovery room for as long as you need to afterwards. It will hurt for a couple of days after the procedure since your uterus is quickly shrinking back to its original size, so plan for missing a couple of days of school/work. After that you will physically feel just as you did before. A month afterwards you go in for a follow-up appointment to make sure that there is no infection (though if you did have one, you would probably feel it and go to the doc much earlier). My follow-up had a perfectly clean bill of health, and I took great care afterwards to be very careful with my birth control so that I wouldn't have to go through that situation again.
As far as emotionally, everyone is different. I was greatly relieved afterwards. At the time, I was just starting college, and there is no way that I could have finished my schooling and taken care of a child. In addition, I was very recently married, so it is hard to say how my husband and I could have handled developing our own relationshiop while also taking care of a child (he was in school also). The first few years of our marrage did have some rough spots (as all of them do) but it was good that we were able to focus on ourselves and our relationship to get us through them. I am now finishing my master's degree (he completed his 2 years ago), and am now pregnant with our first child - which was planned based on the status of our relationship, carrers, and general livelihoods. Being pregnant again does cause me to reflect upon my abortion, but I'm still glad that I got it. It feels wonderful being in a situation now where I can care for my child in the way that it deserves and provide it with a loving, nurturing environment.
I'm sorry that you do not have support from your family - I never told mine. I did find comfort though in friends that I trusted, and in my husband, for whom it was also a difficult decision. The first couple of the months were difficult, but I think a lot of the emotional difficulty comes from the negative social stigma about abortion, and not from feeling guilt about my decision. Contrary to popular belief, Planned Parenthood does not push abortions, and the doctors there are available if you want to ask more questions about your options, the pros and cons of each, and help you with what is right for your situation.
Anyways, I hope this helps, and I only wish the best for you and your future, whichever is the right road for you to take.