That is good news about your MRI.
You have gotten such great advice and I can't add much. As for the cyst, I have one in my sinus and it always shows up on the MRI. Going to an ENT is a good suggestion. I have had the cyst for years and years. I use a cortisone type nose spray and do my Neti pot daily. That seems to keep it under control. The Mayo Clinic website has some great information on cysts in your sinuses.
Wishing you the best of luck.