All successful treatments feel that way, meaning you start feel worse and worse but then you get better. This is really my experience as well.
Ivermectin is max dosed once a day, as it works in the body for up 18hrs. The standard dose p weight is 200ucg. You really do not need more than that.
You might want to try doxy as well for the bacterias that shield the nematodes. If you see no improvement but mainly reactions to it within a month, it might not be needed. It is useful to combine with ivermectin and do them in cycles. Lyme plus nematodes, and added viruses or other parasites i estimate 1-2 yrs min treatment, if you do it intensively. I hope you will get better soon.