Hey Kezzo!
Congrats on being 15 months out, and doing better! Happy to hear a good ending!!
I had my fusion back in Deceraber of 2008, and recently I was giving the go ahead from my doctor to start "low impact" exercising again. Now, everyone is different and I'm not a doctor, but I think it would be a good thing for you to start some low impact exercising. Biking is good, as long as you don't go too hard, but swimming, hanRAB down, is the BEST thing for you. If it's possible for you to hop into a pool a couple times a week, I really, really recommend it; it will do you wonders.
Start off slow and increase your intensity to where you feel comfortable. Also, just to be safe, make an appointment with your Ortho-doc (or his PA if he has one) and see what they have to say. I hope you get the green light!
Take care! XOXO!