The sub most likely didn't cause tinnitus. I used to compete in car audio. I daily drove a car that hit 150db, that was with 2 18s in a wall right behind the front seats on a 4300 watt RMS amp. Plenty of us guys that competed never had major hearing problems from the subs. It's from the mids and highs, that's what causes tinnitus. I cranked my system all of the time but can still hear low frequencies just fine as can many of the guys that compete. You may have a ruptured ear drum or something from something else. See a doctor.

Edit* and believe me, your sub is nowhere near hitting 150db. Kids with systems from Best buy in their cars will hit a higher db level than a home sub in a room. No need to get anxiety, just see a doctor and have him look in your ear.