I decided to try and clean my teeth by letting 3% hydrogen peroxide sit in my mouth for a long time (a little over half an hour) and now my taste buds are mostly gone. is it permanent?

Be patient. The effect will fade over the next week or two with the bodies self healing ability returning things to baseline.

Use a tooth brush or an electric brush with toothpaste mixed with the peroxide. You neutralized the normal acidic flora of your saliva and now on taste. Eat a lot of fruit to return your normal saliva. Don't try home remedies ask tour dentist for advice. Your condition is not permanent, the acid from fruit will neutralize your saliva to normal levels.

The good news is that normal function should return over the next few weeks. if not you may want to seek consultation with a specialist in Oral Medicine. Local Dental Society should have list of Oral Medicine specialists. Please ask your Dentist or his/her Hygienist to create a SAFE and effective daily Oral Hygiene routine for you.