Please help me save my kitten

My kitten has a mouth infection, and it's getting worse overtime.. It started off as bad breath, and I thought nothing of it and simply gave him supplements for better teeth and breath, but as time went on I noticed that he got thinner and more sickly, and his gums began to bleed and drool. I asked online if there was something I could do at home to ease it, because I've taken cats to the vet before for less and it cost us a lot of money. I'm struggling to give him proper care because our finances are going to bills, and soon I'll be moving to another country because of school (I was enrolled in another country and I was supposed to go back, but Covid happened and I got stuck here in the Philippines).

The inefection has started to eat his jaw away and I can see his bone! I can no longer ignore this and I really don't want him to die like this. I know that costs would possibly go under chemical tests, possibly X-ray and even surgery, and I really don't have the budget for it.. Please help me