Your doctor is exactly right! Taper these, withdrawal can be a nightmare. Besides, you were on a very high dosage, the highest dosage tested by the manufacturer was 20mg. I just went up to 30mg because it wasn't working, and it made my hyper. Anything can happen with these things. Your original problem doesn't sound like you needed medication, you needed some therapy but not much more.
It is NEVER a good idea to quit medications like these cold turkey or as quickly as you did. The only way to do it, is with the advice of your doctor and it sounds like he/she is trying to help you. You are putting yourself through much more difficulty than you really should put yourself through. As you taper down slowly, you will really reduce the side effects you are feeling....keep us posted!