Been Treating RI for 4 Months

Hello I was just wondering if anyone out there has every treated a ball python for an RI for a long period of time, with a positive outcome. I have a 7 month old ball python that was diagnosed with an RI back in May. He has been on a variety of medications (oral, injections, and neubilizations), radiographs were taken, blood work was done, and a tracheal culture was done (Pseudomonas was found). I'm currently on a second veterinarian. Clinical signs started with a popping sound and progressed to large amounts of mucous in his mouth. My snake stopped eating, so I have been force feeding him. At this point, I'm just wondering if he is ever going to get better. I'm planning on calling my vet and discussing possibly doing another culture and if maybe IBD could possibly be involved in my snakes illness.