I would give the Inderal at least a couple of months, and most likely your doc will increase the dose, especially since you are on a much lower dosage. My doc said that many do well on 80-120mg. When you go on a preventative med, it always takes a while before you know if it works. Its so horrible to have to wait! BUt what else is there to do?
Have you tried Zomig? I usually use that (I'm just out of it right now), it seems stronger than amerge. I switch between Zomig and Amerge. I only use the amerge b/c it has less side effects for me. Keep trying different meds for abortive type, you should find one that works!