wow ,okay this does sound different .
I too have very fine hair and if I don't use conditioner then I wont be able to comb mine either .
Remember the peroxide and other treatments are going to strip the hair and put it in bad condition and then when it gets wet you wont be able to comb it .
Im really sorry you are going through this .It sounds scary .
Have you tried putting ivermectin right on your scalp ? I would mix it with a little coconut oil because the coconut is good for your hair and scalp and it will be a carrier for the ivermectin .
If you haven't tried that I would give it a try asap .Because if this is a parasite of some kind then you will get confirmation if it either riles them up or kills the little sob's.
I know a lot of people suggest soaking in baths with Epsom Salts and peroxide and other things and I think there is a time and place for it .But just be careful because I think it can spread the parasite and if your issues are strictly the scalp you don't want this going to other areas .
Please try the iver and/or nizoral .But not at the same time
Its too bad that you are having such as issue with combing it because diameticous (however you spell that ;) earth or DE mixed with grape seed oil worked wonders for my scalp critters .But it dried my hair out and fine hair is a nightmare to comb when it gets damaged .
Another thing that helped my scalp was extra virgin organic coconut oil massaged into the scalp and left over night every night .
Does your scalp itch at all ? Or is it mainly the biting and tangling and goo ?