I am not certain as to exactly what you question is, but let me try to help. It sounds like you feel you need to do a parasite cleanse, but when you have tried it before you have had a bad reaction to the wormwood. Is that correct?
I can't judge why you feel you need a parasite cleanse, but if you haven't had one, it's a good idea to have one. There are different ways to approach a parasite cleanse as well. There is not a "single correct" parasite cleanse. In reading the old Eclectic physician manuals, I have found many different approaches. Dr. Schulze's approach is to include the anti-parasite herbs in with the liver/gall bladder formula. It is a fine formula and very effective. My studies have also pointed out that the bowel needs to be functioning properly for a parasite cleanse to be most effective. So my personal recommendation would be to switch over to the Schulze protocol. You don't have to get rid of the GABA. I would switch over to Schulze's bowel program.
Here is what I would do.
Week 1 - Intestinal Formula #1 to regulate the bowels
Week 2 - Intestinal Formula #2 to deep clean the bowels and remove many parasites (keep taking IF#1 to keep the bowels regular as needed.)
Week 3 - Five-day liver/gall bladder - Anti Parasite cleanse
Now there are other things that you can do that are simpler, but probably less effective. Black-Walnut
can be taken, I would recommend tincture form. Lots of fresh garlic as it is a vermifuge (anti-parasite). You had mentioned taking wormwood with bad reaction, so I would stay away from that. To the extent that you take these other things, make sure your bowels are functioning regularly 2-3 times a day.
Also if you want, you can call Dr. Christopher's School of Natural Healing to talk to a Master Herbalis on Monday through Thursday from 1-2pm MST at 1-800-372-8255. The short consultation there is free.
Here is a link to some of Dr. Christopher's materials on Parasites.
I hope this helps with your questions. If I have misunderstood your question, please respond and clarify the question and I will try to respond.