My girlfriend is pregnant and I'm a worthless piece of sh.t?

I am a retired marine and gangster. My baby came into my world a few months ago, and she changed my life i feel like, she got me to stop selling the blow, the crack, the weed, she told me she was pregnant and i stopped using all the drugs. But i work for min. wage at a gas station, she's smart beautiful, and graduated from a 4 year school, where she obtained a DVM and is a very successful veterinarian, she makes 3 times more than i do, she pays our rent, our bills, our car payment. I love her to death, she says she loves me too. She told me to not leave her because he couldn't go on without me, she said "i've gotten to attached, i wasn't supposed to fall in love with you or get pregnant, but i did do not leave me" i say i love her to much to see her not be able to have the proper man she needs in her life, and it would crush my soul to see my child not have an amazing father in their life. i need help, what should i do. how should i react, what should happen.?