If you love a man a lot, care about him very much. Will he become doesn't think too much about you, and don't give a damn. Just do whatever they want. and flirt with other woman and cheat on you? Because he knows you are there, you are a sure thing.
Hello! Please remember that my responses are informational only, we are not establishing a therapeutic relationship.
It sounds like you've been hurt badly by someone, and I am sorry about that. A good rule of thumb to remember is that we cannot change another person, even with love. People change when w ourselves see the need to change (which is usually brought on by being in some kind of personal pain!). Without the experience of this personal pain, we tend to continue on as we have --so how a person has behaved in the past often predicts how they will behave in the future.
Many women believe that they can change a man or that marriage will change a man, but these are both untrue. People change when the cost of how they are currently is too much and greatly outweighs the benefit they experience. Sometimes we reap some benefit from our bad or unhealthy behavior which keeps us stuck in that pattern.
It might be best of you to take a look at why you are a "sure thing," for a man who treats you poorly. If you are loyal, you deserve a man who is loyal!