Hey Jade,
If money is a problem research the internet in your area for free pitbull neutering and if your area doesn’t have free call SNAP! I believe getting him fix will help with his agression and behavioral issues. Please make sure you separate these dogs when you are not home. I purchased a kids baby gate to separate my two pits when i am at work. My pitties love each other but it only takes one toy that they both want and if i am not there to supervise… well you get the hint! I can’t risk that! Good luck to you.