IMO, you need to skip the glue and get used to just taping the thing to your head to start.

The C22 will remove the adhesive by you need to give it time and use a LOT of it.

If you can salvage the unit and not destroy it trying to get the adhesive off, give a go with just tape. Can you sort of brush the hair forward so as not to worry about a picture-perfect hair line for the time being? Walker No-Shine tape is pretty good in terms of not being shiny and these tapes are quite strong, even with no adhesive whatsoever.

You have too many adverse things going on at once here and you are freaking out. Take things one step at a time, honestly its ok to use just tape (if only for awhile) because the clean-up process is much less daunting.

What exact type of unit are you using now (i.e. all lace, poly perimeter lace front, etc...)?