Oh man, I was in exactly the same situation 3+ years ago. Back then I was in a relationship that lasted for almost 7 years, we liked each other very much, but I think we didn't love each other, it was a typical Relationship where both partners were just engaged because they thought it's the right thing to do, and because they were afraid to be single...
I ended our relationship, and decided that I don't want to be an AFC anymore. I didn't know anything about PUA back then, I only found the PUA community a few weeks ago. So I had to learn everything the hard way, and I still have to learn a lot, but it's much easier now with the help of this community
I can't help you with your decision, but I can tell you a few things that'll happen when you end your relationship:
- be prepared for a huge and hard cut in your life, I completely changed myself during the last 3 years, but it was very hard and frustrating sometimes. I even had to take a timeout from girls & pickup for several months at one time because I was suffering from too much stress.
- My sexlife definitely became better, better because I'm a man with a desperation to have sex with as many different girls as possible. But be prepared that you'll not have such a good emotional connection with these girls as in a relationship, that was one of the hard lessons I had to learned. Just Sex or a Sex-Relationship is most of the time not a replacement for a serious relationship.