This cute boy needs help

Feen has megacolon. He also has a slightly narrowed pelvis from a previous injury that I wasn't aware of until a problem began to arise. It has been gradually better medically managed as I've learned more over time, but the damage is done.
At this point, corrective surgery will save Feen from his current irreversible constipation, as well as offer him a more normal life where he doesn't have to take as many meds every day if any, and no more scary and painful vet visits. Anyone would want that for a loved one. He is currently starving as I am forced to underfeed him to prolong his survival until he can get the care he needs. Deopstipation and enema attempts have been thoroughly made this time to no avail.

He has been with me through the darkest parts of my life, and I have gotten him through his. He absolutely loves me, I look into his eyes and he searches mine, he is my baby and I will do anything to save and protect him. We are always near each other, he likes to hear me play music or talk to someone. We keep each other warm all winter, I share my blankets with him and chase him around when he wants to play. He makes everyone in the house happy. When he has to stay at the vet, everyone is immediately affected by it. He seems to be everywhere at once and right next to us for company if we get up or make noise.I love him so much.