Nice effort dear friend. You started with so many heartfelt questions, that almost every one of us once had and were burned with. But in this poetical endeavour you answered all your questions. You revealed the causes of all your sufferings:
"I loved you so much that I gave you all of my money
I loved you so much I pretended everything was sunny"
“paid all your bills and rent”
“never asked where you went”
“you make me look dumb”
is you. The brutalities all belong to you, not him. You allow him ( even empower him) to ravish you, take advantage of you and still give him your unconditional love:
“I love you when you choose to cheat
I love you when you're not discreet”
How would you expect him to better himself, even if he love you? You're even authorizing him to go ahead and cheat. If you ask an average person to cheat, be sure that she/ he would soon or later comply. Life is complicated and heard even when you try to control yourself never mind when you have permission.

This self-harming love is not healthy. Loving a brute is not love. You are the problem, when you fall in love with a brute. Like a person who like a greasy hamburger.
You have a great ability to love and your love is amazingly tolerant. A healthy love needs those admirable abilities; life is not a Fairy tale you know!! But your ability to love, the way that it is now: regardless, if he is like beetle or vermin inside but better look like butterfly or hummingbird outside, must turn inside out.
Then all these extraordinary tools that you have for love would come handy.