<human>: I've been going out with my girlfriend for 3 months now, but i've started to realise that i'm not enjoying the relationship as much as i did at the beginning of it. 

  This isn't just a "I'm bored of this girl" situation, there have been things that made me understand that I can't go on with her anymore. For example, we argue about every other topic, and not just little things either- recently we've argued about how I spend time with my friends, and how she doesn't like me talking to other girls. Finally, the other day when i went to a New Years Eve party i found myself flirting with this one particular girl, to the pointing of having to stop myself making out with her. This made me realise that if i'm flirting with other girls then maybe I shouldn't be continuing the relationship. Not only that, but I had more fun with this girl then i did with my girlfriend for the whole of our relationship so far.
  So the question is, how should I end it? I can tell that my girlfriend is still interested in me as she still tells me how much she loves me and how i "started [her] year off perfectly", so I know that when I do end it, it will be rough, but I don't want to lead her on to think that this relationship will work until the end of time, figuratively speaking.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: My girlfriend is still interested in me, but I can't return the feeling. How can i break up with her without making it too rough for her?