<human>: Summarize the given text in a few sentences.

I've been with my girlfriend for nearly three years. We'd always talked about staying together long term, getting married, and having kids and so on. We'd also talked about trying an open relationship, at least for a little while.

A few days ago, she admitted that she didn't want to try going open, and that she'd never really meant it when she'd said it before (or at least, it was self-deception). I should have known she'd never want to try, but I guess I was deceiving myself as well.

The problem really is that our going open was a little bit of an escape valve for me, and it meant I never really had to confront fully committing to her. We also have pretty different sex drives, and I worry quite a bit that in a few years I'll be posting to deadbedrooms instead of relationships.

I wonder if someone who's been through this before can tell me:

1. Will this nagging fear go away, and will I be happy with my current girlfriend?
2. Does the desire to sleep around while you're in a committed relationship ever go away?
3. What should I do about the sex & libido issues? 
   
Other relevant things:

* I've been in open relationships before, it never really seemed to be an issue.
* Other than this _one thing_ we have an amazing and fulfilling relationship. I really do love her, which makes this such a difficult choice
<bot>: I'm not sure if I'm ready to settle down with my current gf. Will the fear that I'm missing out haunt me forever?