Now, I don't know you, or your situation, but first thing first...
1) you have to stop lying to yourself, before you can stop lying to everyone else... you have to ask yourself: "whats the real reason I'm not moving in with her?" is it that you think her AND her kids are too much... do you think she is too much... are you being influenced by others... cause, the fact is: No matter what a million different people tell you, you have to do what YOU want to do... It isn't up to me, or this person or that person, or your neighbor, his dog, your family, or anyone elses decision, but your own...
What makes you think that a little more effort from both of you isn't going to help you? I mean, just think about it this way... If you get a cat, and if rips up your favorite shirt, you don't just toss the cat out, you teach it boundaries, and it'll teach you yours... if you've ever had a cat, you know what I mean... People are sort of like domestic animals... You have to bend a little to have the other bend a little or it'll run away from home or die... then you'll be alone... see what i'm saying or am I ramblin?
Obviously you either care about her so much that you ask a bunch of bassically complete strangers for love advice you you're so confused that you have to spread your "dirty laundry" around to air it out...
Like I said before, you can read this post a hundred times, but it's up to you to do whats best for you. Hope I did help, but if not I'm sorry.