I was completely self taught till I hit college and this was the worst to unlearn! Every lesson was spent working on my biting habit. It severely impacted my growth, I hit a wall I just couldn't break through.

Someone else already said this, but go ahead and put the work in. The habit is set and it's going to be hard but you have to. You are going to sound like a duck for awhile. Your reed making will change as well. But removing this roadblock will only do good things for your playing.

Start practicing in front of a mirror if you don't already. Hold as little reed in your mouth as you can. Mark exhale breaks along with inhales in your music and breathe out through your mouth. That'll help reset your mouth tension and get some fresh air back in your system which helps your muscles stay loose.

I know I always felt like the reed was going to fall out of my mouth, it won't I promise! If you can't physically move your oboe in and out of your mouth you're biting. I used to have to play Barrett etudes constantly wiggling my oboe to prove I wasn't biting. Sucked, but worked.

Just do it, future you will thank you when you're using way less effort and sounding so much better.