Do something physical
I'm probably not the typical programmer but I need my occasional adrenaline/endorphine fix like most people need their daily coffee fix.
My hit list is, Snowboarding, Wakeboarding, Hiking, Riding a bike, Running, Riding Motorcycle through mountain canyons, Going out dancing (bring a guy who can dance, it works better that way), Sex...
Go new places, see new things, meet new people, get the blood moving, face your fears (or just do something that just scares the crap out of you). Cut the cable (by cable I mean TV).
Seriously, programming is not an active job, balance it with an active lifestyle.
The best part, new experiences and challenges are good for brain health.
Get a paintball gun, find a paintball field and shoot some people. It's really fun (as long as you're not too afraid to take a few hits too).
Find a mini nascar (go kart) track and see if they have cars that you can take a few laps in. It'll probably be one of the slow versions (45mph) and you'll have 9 year olds blowing by you going 90 but it's really fun. Those little buggers are pretty serious about race day.
If that's all too intimidating for you, find a local bar with a free weekly poker game, it's a lot of fun.
Worst case is, you have some really interesting/funny stories to share with others.
If you want to do something interesting and geek out, build something cool like a jet powered go kart or a gatling spud gun.
I honestly don't understand how most programmers are supposed to have a social life when all they have to talk about is programming. Do something interesting and you'll attract interesting people.
Having friends and an interesting life will make you happier, which will help you be more confident, which will make your work life better. Plus, the new challenges will actually make you smarter.
Edited to a female perspective because the Op is a girl. My bad... ;)~