glass or digitizer or both!?

I have a galaxy s9 that I've dropped several times. it has several points of shattering in the glass on both front and back, and most of the corners front and back have large chunks of glass missing. this last fall cracked the front glass right above there Bixby buton and now has a large solid black area that looks like a big blob of ink and runs downward about 2 inches then trails off into a dark green color befor ending. the touch screen still works fine including where the giant black spot is. my question is can I simply replace the glass only or do I need to get a digitizer as well? I don't have phone insurance anymore and can't really afford to pay to have it professionally done where I live ($450 just to change the glass only) since I already have the glass screen for both the front and back (without digitizer) I am hoping I can just switch the glass and be good to go. I understand it's not an easy or simple job but due to restricted funds I don't have many other options. so if someone could tell me which component/s I need to replace and possibly point me in the direction of a very good step by step tutorial that I could follow along with or watch for the info and know how to complete this job successfully id surely appreciate it.

thanks

leilei