Single Lesbian Looking to start family

Hello I am looking to start a family on my own. In my past relationships, all of my exes had kids. I would get attached to the kids, then they would leave. I am seeking someone to help me have my own child. A child nobody could take from me in the event they choose to leave. I have tried in the past but was unsuccessful. I am graduating soon from college and would like to start my family. Please if you can help, please let me know.