I have one more year left of college, what can I do to enjoy it?

I'm the type of guy who just existed in high school and hated that time in his life. The first three years of college were better, but only just. Freshmen year I didn't do anything with myself, focusing on grades instead of friends. Then, I became an RA halfway through Sophomore year and that consumed my life. I hated every second of it, I was more miserable and lonely than I had been before and I was expecting to meet people I could rely on and make friends with and didn't. I was recently fired from that job due to a communication error and had no support or help from the people I worked with. I thankfully still had my friends and family, the latter of whom took me in and let me stay at their house off campus. In the past few months, my girlfriend who started out as my best friend dumped me and has started dating another guy and I have feelings for her still. I've signed a lease on an apartment and have a temporary job at the school bookstore when I come back, but am still heartbroken and in need of a part time job. What I'm trying to say is this, I've not had a good college experience up until now but since I have an apartment I expect things to be a little better. I want to make my senior year count and one to remember. I want to spend it working hard and playing hard, getting good grades like I have but I also want to go out there and make friends and have a good time. I haven't made many friends, but I'd like to do that. I really want to enjoy this bittersweet, last year. What can I do to enjoy it to the fullest potential?