Re surgery of Left ear Mastoiditis.

7 years back I had surgery in my left ear due to pus discharge, doctor has performed Mastoiditis surgery and it was fine for 6 years . From last month I'm feeling kind of wetness in the same ear and pus started discharging again. Went to a ENT doc, he said it's Chronic Mastoiditis and suggested X-ray and X ray report said : X-RAY MASTOIDS ( BOTH SIDE ) BILATERAL Mild sclerosis of left mastoid cells. Otherwise mastoid air cells on both side are pneumatized. No obvious bone destruction. Dural and Sinus plates are intact. I have hear loss in both ears, left ear hearing is better, but right ear hearing is worse. I was planning to get my right ear surgery for better hearing. But left rear disease seems to be prominent. If I get my left ear surgery done for Chronic mastoiditis, how much would be the recovery time ? Will the hearing gets improved more or will it get worse ? Post the left ear recovery I'm planning for right ear surgery. Need suggestions. Thank you. -----------------------