Fix coarse and shiny hair + reglue wig

Hi so I originally asked this question a long time ago and I’m finally now doing it in an attempt to fix my doll. For background, my doll is a retired paradise galleries wigged doll. His wig has fallen off (somehow??) and I will be attempting to glue it back on but I wanna fix the texture of it first. Someone told me to use conditioner and fabric softener but I do not have the softener at the moment, is there another combo I could use? Also what type of glue would I use to keep his wig on? Luckily it only a partial fall off but it scares me every time I change his clothes. Help or tips would be appreciated !!