iPhone 4s Spotify app crashing; music disappearing; redownload process wont save

[qwicksand]

music randomly deleted off of phone, app crashes everytime it tries to redownload songs, and then it starts over every time i open the app back up. stuck in a loop.

I'm not sure if it's my dinosaur iPhone 4s or the Spotify app itself but there seems to be no sign of progress in my offline music becoming completely redownloaded. It was all downloaded just a few days ago, but for some reason, the app crashed in the background while another app (Facebook) was being used simultaneously, which the iPhone 4s for some reason cannot seem to manage, and after that a bunch of music disappeared until I had my laptop Spotify app open along with my iPhone Spotify app.

However, it gets to about 120 of the 857 songs needed to download, at most, and then the app crashes for no reason, or if the phone goes in to sleep mode, it kicks me out of the spotify app. Both somehow restart the download at 0 songs with no progress saved for whatever reason.

I dont know if those songs will remain accessible on my phone if my laptop is not on nearby with the spotify app open simultaneously.

Any suggestions/help would be greatly appreciated.

P.S. Getting a new phone is currently not an option.