My betta is dying. What can I do? Please anyone help? :(?

Unfortunately, most vets do not treat fish, but please call around and try to find one that does! First thing to do is check your filter. If it is malfunctioning in any way, he may just not be getting enough oxygen. Second, check the PH, temperature, ammonia, and nitrate levels in the water (they have cheap, easy tools to do these at any pet store). Lastly, it may be his swim bladder. Their swim bladders help them maintain their orientation in the water. So if he is remaining on the bottom, that is likely the cause. There is no treatment if it's caused by a tumor or genetic issue. HOWEVER, if it's something else (constipation, infection, etc) it is easily treated. Checking the filter and water like I suggested could remedy the problem. Also, get some brine shrimp to feed him, which will clear up any constipation, if it is there. It is okay if he doesn't eat much. Most animals instinctively fast when they are sick. It may just be his way of helping himself get better. Good luck, I hope the little guy makes it!