Wow, I need some prozac after reading that.
1) If your grades are starting to suffer, fix that first. You're at college for an education to better yourself for the future. Grow the hell up and top wasting YOUR time, the OPPORTUNITY that your scholarship provides, and YOUR PARENT'S money.
2) If your having issues with money, fix that next. If you're not willing to take responsibility for money issues, how do you think you'll be any different in a relationship? Go read one of Larry Winget's personal finance books and take responsibility for where your money goes.
3) I may be misinterpreting what you said, but it sounds a bit like your parents may have micromanaged you all though your growing years. If so, then yeah, that sucks. It also sucks that your parents denied you the needed interaction with girls while growing up, and now are wondering why you're not engaged yet. That said, it's still YOUR life, so if you want to change it badly enough, you CAN do it, as long as you realize this is going to take a lot of work.
4) Acne: Proactive my friend. Also, consider this: I had a bad patch of body acne on my back when I was growing up that hung around until I was 25. Acne meds didn't do anything. At that point, I saw a dermatologist about it. He put me on a course of antibiotics that cleared it up within a week (acne is just a skin infection, after all), and I never had issues with my back ever again. Worth checking in to...
5) If you're a natural red-head, don't dye your hair, it looks weird. Being fair-skinned like you, I know I'm never going to have a deep tan, but a little sun never hurts. Just don't sunburn yourself, as you'll pay for it later in life.
6) Something I've noticed is that all the red-heads I've known in life that are pretty successful have the whole "cocky-funny" thing down. Don't be a class-clown, as that is a DLV, but instead make fun of life's little moments. Read up on the current events, find some WTF moments, and script up some funny stories to entertain people with.
7) What HabitualJerk said about being sexual is golden (to paraphrase Van Wilder, I'm writing that down!). If you're following Mystery's formula, once a dame is in the Comfort stage with you, start with Kino. Touching helps awaken sexual feelings....if you don't believe me, just ask yourself how good you felt when a pretty girl hugs you.
8.) STOP BEATING YOURSELF UP ALREADY. Negativity is self-perpetuating....it will never stop unless you take action. Take responsibility for your flaws, sure, but don't dwell on them. Take a sledgehammer to that boulder of self-doubt you've been carrying around on your back all these years.
9) Start small. Do the Newbie Mission first (I'm doing that this evening at the mall), then work your way up little by little with your social skills. You didn't become a baseball star overnight, you had to work at it a little at time. Same thing applies here.
10) You're in the right place. We've been (and I am!) in the same place before, so we know you can overcome this. Keep posting.