Hi mother2kamryn,
What you are describing -- lying at the bottom, on its side, struggling to come up, not eating -- sound like my betta a week or so before he died. A gourami is also a labyrinth fish like a betta. You could try QTing the gourami and giving him some medicine. Jungle Fungus Eliminator is a yellow powder, and it treats bacterial and fungal infections. I thought that my betta may have had a bacterial infection, so I tried that. I've also used Kanacyn, an antibiotic (open the capsule and put the powder in the tank.)
Kanacyn and Fungus Eliminator have worked miracles for me before. They didn't save my betta in the end, but I wanted to try something, and those 2 meds worked before for me.
Another simple thing you can try is to lower the water level to about 6 inches or so (be careful if you have a submersible heater -- unplug it first). The gourami needs to get to the surface, like a betta, to fill his labyrinth organ with air. If it's easier for him to get to the surface, that may help to perk him up. If not, it may make him more comfortable. If you do this, I would keep the water that you take out, and if it doesn't look like it's helping, then replace the water so you can keep the heater on and at least keep him warm. Hope this helps a little.
P.S. I do agree with Menagerie about inbreeding and poor genetics. My very first betta got finrot about 3 weeks after I got him, and he always had it to some extent. He must have had bad genes or something. He was happy and active, and I learned a lot in treating him. I had him for 1 year and 10 months. Near the end he acted like your gourami, and I thought that the almost constant treating I did for his finrot may have caused a super-resistant bacterial outbreak in the end...I'll never know. But I know how frustrating it is to see your little fish friend sick. Good luck in treating him.
