You can do a backup in TWRP (as explained in the twrpbackup guide), reinstall the OS as explained here (or first you could try a dic:factorydatareset) , shortly check if your issues are solved, and restore the Data partition only from your TWRP backup (in TWRP, tap on Restore, then tick only Data and untick the rest, and swipe to restore). Though be careful, your internal storage won’t be saved and you will lose it, except if you follow the twrpstoragebackup tip, or if you just simply save it on your computer by copying the files and copy it back onto your phone after.
If you feel like all this is too complicated, you can either ask a fairphoneangel that would be in your vicinity if he/she could help you (well, these times it’s a bit complicated with the pandemic), ask further questions that I or others will be glad to answer 
, or forget about it.
Did you have any problems? At least you managed to install TWRP.