hey, I'm really sorry to hear about Jimmy's health problems. I have been there myself with my bridge bun Snoopy. its so stressful and indeed expensive. at that time I did not have insurance either, which made it even more difficult. I would consider contacting petplan as they have covered dentals before. they say they do not cover it in their terms and conditions, but others have had some costs covered, medicine and anaesthesia for instance. if Jimmy has been for dental check ups (making sure his teeth are ok) etc sometimes they will accept. I would give it a go in all honesty.
sadly with teeth issues, it can be caused by multiple problems. hay is one, but so is breeding. due to breeding we make their heads smaller and rounder for the "cute" effect. this can cause their teeth being poorly aligned, roots to cause troubles, or even their teeth to grow into their jaw. sadly for my little boy, that was likely the case. he was took weak for us to proceed with any treatment and wouldn't survive a GA, so we decided to PTS.
I would really get some x-rays done and get his teeth looked at extensively under a GA. when they are awake they can't see most of their teeth, I think only the first back ones. under a GA they can get a really good look without a wriggly bunny, and some x-rays will show how the teeth look/any problems in his jaw.
on the page one, you said "taking treats and eating his pellets and herbs without flinching." I think that could be your main issue. its hard, and he will not be happy at you, but you really need to stop giving him any treats and hardly any pellets. that way he has no choice but to eat hay, and eventually he will. you can also try lots of different hay, they each have their own preference. mixing in many different types and forage is really good for them in encouraging to eat.
honestly I think at the moment he isn't eating hay because he is getting pellet and treats, the good tasty things, rather than eating hay. if you offer a kid a lot of candy, they may try to wait out until they get candy rather than eating their main meals for instance, or throw a hissy fit for not getting candy. bunnies are much the same. treats and pellet are literally bunny candy. so you do really need to cut it out completely.
you can also almost completely cut out pellet, and offer science selective fibre first sticks instead. they're meant to be a supplement to pellet. they contain a lot of fibre and to claim to be good at wearing down teeth too.
bunnies aren't stupid enough to starve themselves to death, if you force them into eating hay, they will (unless they have an underlying health issue).
you will unfortunately be paying out for constant dentals until you "fix" his diet and get him eating a big amount of hay. along with that, not eating hay can cause a huge amount of health issues which I'm sure you know about. not only their teeth but it can cause tummy issues too such as GI stasis and having an over full tummy. they really need to eat hay and nothing can supplement that.
I think after you have been to the vets, completely change his diet. perhaps even speak to your vet about his diet also? they can give you lots of tips and pointers and help you change his diet and hopefully get him on the right track.
if it is just spurs, you might be able to correct it now by upping his hay.
good luck, lots of vibes for you and him.
