Young bodies are great things! They can heal themselves much quicker than we old people's old bones. But you got to give it a chance! I know 3 months, at your age, sounds like a really long time. Some of us have been dealing with our back problems as long as you've been alive!
Believe me, you really don't want to be like us if you can help it.
I'm not a doctor, but I'm guessing that a spondy with a small fracture is something that someone of your age can heal from 100% and for good... so that you're not bothered again by it in the future. So, I know it's a drag, but please try to do what the doctors say. Being a senior is better anyway, and you'll want to be healthy for that!