Listen, don't you ever change.
If you're friends really are your friends, they don't mind your personality. I know how you feel. I can't really say I'm a nerdy type but my friends do sometimes warn me about my childish jokes and other stuff. But they're still my friends and won't stop being just because of those tiny details.
If you change, people will like you for the person you are not! And you don't want that, do you? Being nerd isnt bad. It's just being good in other matters. You may lack social pop culture but you're good in stuff you're friends will never be. It'll take time for you to adjust yourself, but don't try and force it. Let it be step by step.
For example, I entered college with the theory that drinking and smoking was just bad and I was never gonna do it. I don't smoke and never will, but I begun drinking socially, which is a thing I never thought I would be capable of. I might say I changed a bit. And that bit brought me opportunities of new friends and new places to go out with them...you see, of course this is just an example, but the bit I changed granted me to go out more with my friends and experience the same stuff they did. I wasnt forced. I thought...what the heck, why not? Let's give it a try.

You can do the same with other stuff. Not with drinking, but with getting used to talk about pop culture in general. Try watching the same series your friends do. Of course they may suck, but if you never tried u cant deny it. Or try telling ur friends about ur tastes and maybe ull even make them have a bit more in common with you.

Just my opinion... ;)