I agree with ggreg. You should be over the worst of it. Why start it all over again?
I have been taking Klonopin for a number of years for different reason than you, and I have gone off the drug several times, so I speak from that frame of reference.
In my opinion, once you go off the drug for as long as you have, you should just stay off, instead of going back on it and tapering. The reason I say to just stay off is, because you're already three weeks in, and it takes me just a month to get over the worst of it, that means you're almost there. Yes, your body is having withdrawals, but those will go away in time. Some remnants stick around a little longer, but the worst is nearly over. That's what all your discomfort is, withdrawals plain and simple. And even though you've just now resumed it for a little while, you can still drop it, and you won't have too much longer to go until the withdrawals stop.
Tapering is fine when you're first getting off any drug. Even tho I don't think you should do that now, I'll tell you what they recommend on websites devoted to getting people off such drugs. You cut by 1/4 tablet for several days until you feel "normal" again, then cut 1/4 again, and so it goes, until you're all the way off. But either way, you're going to feel the withdrawals. Some drugs are rather dangerous to do it any other way than tapering. But with what you're taking, obviously you can manage "cold turkey," since you've already endured it, so I don't think you should drag out what you've already done.
As for your migraines, there are other drugs besides the triptans. Here is a website that talks about all the different medications for migraines and what effect they have and so on. Surely from the list there, you and your doctor can try one or more of those. They would also lessen some of the effects of your withdrawals, since they treat your headaches.
www.healthcentral.com/migraine/find-drug.html
I hope this helps you. Just hang in another couple weeks, and you'll be through with it.