I don't feel like I used to about her

Hi all, First the background. I've been dating my g/f for about ten months now so we are pretty serious, firstly I asked her out but as she'd been hurt before she said no and just wanted to remain friends, but the fact I actaully did stay m8s with her and didnt just go looking for another girl made her realise that she did want me after all. Another point I must stress is that she was ready to give up dating but made an exception for me, not to be bigheaded, this is just what she has said. She is 25 and I am 20 btw. So, the problem is that I realy love her and care about her, I know she does about me back but I dont think I fancy her anymore, like we still have sex etc but when I look at her body I dont feel turned on like I used to and Ive started masturbating alot more and am thinking of sleeping with other women etc, not actually doing it but imagining it. I'm torn between just telling her this and being honest, yeah she'll probably hate me and yes it will break her heart so badly but its the honest thing to do. Or I feel I really should stick at it for a bit longer cos I owe her that much and see what happens bearing in mind ive been feeling like this for about 2 weeks maybe. I really want this relationship to work and would try anything. Any ideas/help would very much be appreciated. Thank-you for any response, J

Hi I don't know if I can help but sometimes it's good to hear views from the opposite sex. Firstly has you're girlfriend changed physically or emotionally since the beginning of the relationship? Secondly (and I ask this because you have only recently started feeling like this) Have you changed, or are in another situation, like your job or where you live, maybe your views of what you want in life in general are changing and different from hers. You must take in to consideration that you are younger than her and could still be growing (meant in a completely non-patronising way) but chemical balances and hormones don't level out in mena nd women until they're about 23. I see why you are so troubled because you are worried to leave her because if how sensitive she is towards dating, this seems like because you are worrying for her feelings that you must really love her. If you didn't care for her you would leave and not think twice. I truly think that not fancying her is just a temporary thing and if you really do love her sooner or later you will start noticing all those little things that you used to when you were first crazy about each other, sometimes other stuff does take over our minds and we need to set aside those feelings but they are still always there. I hope this has helped, I know what it's like to feel confused and unsure of a relationship's future.