You've had a lot of bad luck with relationship because you don't even have a good one with yourself. You don't respect yourself, you don't love yourself, you don't believe you deserve a good man that will respect you and value you. Since you don't respect and value you, you are attracting like.
What was your life like when growing up? Do you have two supportive and loving parents? Are they good role models? Have you ever had therapy? Do you know anything about nuturing you inner child?
I don't think he understands how much I love him and am willing to change any imperfection of mine for him..
You can't change for "him." You need to do that for you (with the help of a professional or with some heavy duty reading self-help) You can't get better if you're talking to him. He's toxic to you and you to he so forget him and work on you or this will keep happening to you.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion