You are your best friend, your biggest supporter, your ride or die. You may have others in life who will treat you with the respect and reverence that you deserve, but no one can love you the way you love yourself or treat you as well as you can treat yourself.
Do you think that if someone truly loves you, they would cheat on you? Going further, if your partner truly trusted you or believed you both had an unconditional love, a very accepting love, do you think he would have kept his bisexuality a secret?
You, my good friend, have just hit the nail on the head. Yes, you should focus on the unconditional, non-toxic love that you can give yourself but also on forgiving the past hurts and experiences inflicted upon you by your parents.