A lot of people go through unnecessary difficulties because they put up with being treated negatively or poorly. You show other people what you think of yourself by how you let them interact with you. The key to being happy in life is to love yourself so much that you realize how important you are and, by extension, expect people to treat you well. This doesn't mean that you act stuck up or like a prima donna, just that you're happy and balanced inside and are able to build positive relationships.
It can be difficult to break the patterns established through many years, but a lot of the things you've always done or accepted are not the final chapter in your life; you can change things around by looking deep inside yourself and deciding to follow a new path. Stand up for yourself and never let someone else tell you that you don't deserve to be treated well. Get to know who you really are and set a new course, you're worth it.