Maybe I am just not made for a gf?

[NunezJ]

I this particular case, you've just picked the wrong girl. It took me a while to understand that you can't make it work with each and every person that you like because we all have different characters, some of which are getting well while others are just incompatible. I used to have partners, and some of them totally rejected things in me that other ones totally adored. So, your objective is to find a girl that will live your serious attitude.
In general, just try to be less serious about yourself. And understand that people need their space and privacy. It's totally normal to feel the urge to see your partner every day, but try to give her a break. It will help this relationship last, believe me