I'm not branding you a bad person, I'm saying that you're a bit overemotional and kitty-whipped - by someone who obviously doesn't care as much for you as you do for them - there are few things more uncomfortable to see. I appreciate the first relationship can be a tough one to end, but the way that you behave in this first relationship will have a massive bearing on subsequent ones, if you make yourself a pushover, for women to abuse your kindness(read: weakness), then you are setting yourself up for a life of being the *****. You don't want that, I don't want to read that.
Also, you had the upper hand in the breakup - until - you started trying to get her not to see that guy... Then you become the grovelling worm again, and that is not something that women respect - hell, they respect/love someone more who slaps them in the face. You're only hurting yourself by being so 'caring'(read: pathetic).
Also, in terms of general comfort of a relationship, it's a pretty good feeling having a girl being your woman, holding the dominant manly position, rather than spending your time being wussy.
Also, it's going to be the routine that you miss, you've forgotten your friends and how to spend time on your own - this is something that women bypass by jumping onto the next rigid branch they can find, to their own detriment. If you can't spend time productively on your own, you're not really worthy of respect (which 80% of women cannot do it seems), just accept that it's something that women don't do, but something that will make you happier and more centred in yourself.