Several years ago I was in the middle of moving houses, and preparing for an early trip the next morning. Middle of the night, I began vomiting and shortly was in so much pain I couldn't remember my own name. My wife took me to the ER, and ended up with surgery for a kidney stone, and installation of a stent. I contacted the chief pilot who said "good luck, and let me know when you get your medical back."
Whaaaaat? It's just a kidney stone.
Not a chance. I ended up working through my own AME and a union AME, and it took about three months, three surgeries, and removal of the stent (which turned out to be the worst part).
Your AME should have helped you resolve this. Don't ever use that AME again, and make sure you let others know not to use him, too. AME's like that do not deserve the business and should be avoided. Dump him. Like a hot rock.
In 2015 the FAA authorized AME's to keep an airman in service even with retained kidney stones so long as the airman can be shown to not be expected to release any more stones. The simple breakdown is that if you had a kidney stone and can show that you it won't be a problem in the future, it's a matter of providing the FAA the documentation, and that should have been handled by your AME. If you have a recurrence of kidney stones, then it triggers a bigger problem; cross this bridge first, and that one when you come to it.
There are services that can help.
If you're an AOPA member, then member services helps in cases like this, and there's an assistance program for a few dollars a year that helps with medical, legal, and all kinds of things. Well worth it, even if you only use it once.
AMAS, Aviation Medical Advisory Service, may be able to help. https://www.aviationmedicine.com. Several pilot unions retain their service.
Pilot Medical Solutions (https://www.leftseat.com) specializes in assisting in cases like this, as well as special-issuance medicals and waivers. You might contact them and see how they can assist.