Not in love anymore, what to do?

So Ive fallen out of love with my current boyfriend of three years. Weve been through a lot together, and I love him as a person and never want him hurting and want him in my life.

But since about October Ive discovered Ive just fallen out of love with him. Theres a lot about each other we dont like, we fight often, and I cant be the person he wants me to be and I know he cant be the person I want him to be.

But that was mostly overlooked by sexual passion, habit, convenience. My family loves him. Everyone expects kids and future, something that is my fault for pressing for.

And now Ive got cold feet. The idea of moving in together exhausts me. Having kids with him sickening. I hate being in bed with him.

But, heres the kicker: in walks someone else in. She came into my life in August, instant connection. Its only grown as we talk every day. Shes got a boyfriend of her own (were not new bisexuals either, were both pretty well established to everyone in our lives as preferring women, our boyfriends are our exception).

But recently, its gone from loving each other and being close to being in love. Shes leaving her current boyfriend within the next couple of weeks. I want to leave mine.

The problems:

i have a trip to go to bought by parents with him in March.

My parents adore him

i dont want to hurt or disappoint anyone and I know I will.

But I do love her. She makes me so stupidly happy. Despite everything, Im happier now.

What am I to do?