I am yet ANOTHER parasite host(ess) dealing with much the same issues. It really doesn't seem to matter too much exactly what these things are. They have several life forms and stages and quite difficult to get exact answers.
Luckily (!?) it doesn't seem to matter what you are killing, just kill them. I don't think we are ever going to kill them ALL off, but we CAN reduce their numbers so they are not such miserable squatters and maybe we can reduce their rate of replication.
In any case I have used Ivermectin ALOT without any problems. The oral horse gel was not very effective for me and according to the medical literature, poorly absorbed. You CAN try taking it with the 40 gm of fat. I have moved on to the injectable Ivermectin which is taken subcutaneously. Now, THIS works! I've been taking it every 3 days for several weeks with excellent results. Remember IVM kills adults, so you have to come back for the others later. Hang in there.