How do you decide to settle with a partner without fearing that they will become abusive?

Idk I never dated but it's so scary when people describe how their partner suddenly started being a different person and once you are married and settled it's hard to get out. It can be people who you'd never expect to do that. Technically you can divorce but being a single parent is hard. And if you have a house together what happens to it and to your loan? It's so much time wasted if you divorce after years. I don't know what to do in my future it puts me off from dating even though I don't want to be single all my life.