Hi, If there’s a reptile store near you you could go there for a second opinion on if your snake is healthy or not. Ofcourse they are not vets and will not be able to treat your snake but that way you can get a second opinion from someone who has lots of snakes and experience. You’d probably have to ask them if they have experience identifying health issues but if you’re lucky they will look at if your snake is healthy for waay less money then a vet would charge. Where I live there’s a reptile store who has experience with snake health and would be willing to look at if snakes are healthy or not healthy for free. Maybe there’s something similar in your city. But don’t forget that they’re not vets, just a second opinion.
(Also wanted to say that your snake is so lucky to have a home with you since you put your snakes health first)