What to doStuck in a rut not sure what to do

Hi all, any help and advice would be appreciated....

I have been in a relationship for a little over five years with a girl. She is pretty,great values and I can trust her totally.....we also have a little girl together who is 2 and a half......

My best mate set us up as he thought I should settle down with a " nice girl "
Things soon developed and at one point I was in love with her very much but there has always been something missing......when our little girl was born I was the happiest man alive and I was so happy with my life I couldn't see myself being anywhere else. My gf found motherhood hard and I tried to support as much as I could. We became more like friends ,hardly any physical contact not even a cuddle really. I tried to talk to her and tell her we needed to sort this before it was too late. We didn't have sex for over a year and I just wasn't happy with how our relationship was going. I have put up barriers now and six months ago told her I was on the point of leaving.

She was distraught and wants us to sort things and not loose me.
The problem is there's never really been that "spark" yes wen the relationship was new it was nice but never that real spark.

I'm not a nasty guy at all, but I do now find myself treating her like I don't want to. I snap at her and fly off the handle for the smallest things. Sex was never exciting just ok but I just don't want it now. I love and care for her but just don't think I'm IN LOVE with her...I love and adore my little girl so much.... If I leave things will be so different with my little girl......I won't see her and be in her life like I am now......am I staying for her or me.....me because I don't not want to be with my little girl. I know kids adapt but I think u know what I mean?.....

We have a house morgage etc all very complicated. I just feel if I stay I'll be in an unhappy relationship but will have my daughter in my life......but if I go I might find a happier relationship but will not have my daughter in my life like I want......

Please help.....if you need to know more ask

Cheers
I've built up walls after a year of trying and trying.

You'd be surprised just how many people feel exactly the same as you. Not always for the same reasons but the actual situation. The tug of love between you child/ren and the needs you have of your own to maybe try and move on to a happier place in your life. It often does feel like you have to make a choice in which you can never be totally happy; in your case with you either being with your child in the family home, but seriously lacking in your relationship with your partner OR being a part time dad which you don't want; but which may allow you to find a new love or be on your own for a while! I'm sorry I don't have a magic wand and myself and a couple of my friends have this on-going discussion ourselves about our marriages/families/children. It is so hard, the toughest decision ever and I think it's a case of 'you're damned if you do and you're damned if you don't'. Have a serious think about how your partner would treat you if you were apart and how easy or difficult she would try and make it for you to see your child regularly. Also, if you stay do you believe you could work on making things better with time, or is there not enough there for you to make it work. Friendship is a big part of a long term relationship and what you sometimes lack in spark you gain in understanding, trust, loyalty and that very special bond. However, you are not being true to yourself or your partner if you pretend to be happy when really you're not. Not only will you probably end up resenting her, but she will be more hurt if another 5 years from now she finds out you've felt this way for so long as wasted her time and yours!

I can't make it all better I'm afraid. Just look beyond the right now to the 1 year from now, 5 years from now etc etc.