I think my boyfriend makes me hate myself.
Are you being serious? Why does he make you hate yourself?
He makes me believe it's OK to say bad things about myself
It is very cruel of your boyfriend to mistreat you in this manner, but you need to remember that he doesn't control who you are as a person.  It can be unhealthy to believe in the bad things he says, so if this continues, or if you start to doubt yourself, it might be best to end the relationship.
Fuck that, you don't know him or our relationship. We have been together for so long now, we can't break up.
There is something called the sunk cost fallacy, where one believes the time put into something it too much to abandon, even if the latter choice is better. I believe you really should break up, your boyfriend should be someone loving and caring, not manipulative and abusive. Don't you want to find someone who will think the world of you instead and treat you well?