Cant access email to update recovery info

My yahoo mail app.keep restarting numerous times in a few mins.(app.restarted 177 in 4 mins).i tryed evetything to reslove this issue.but i ened up haveing to uninstall.so when i reinstall the yahoo mail app from the play store. its asking me for a key code???.i added my new cellphone number and an alternative email addy.but for some reason they are not saved. so i literally have no way to get back into my account to try again. and update my recovery info.( my question why cant i use my security questions i have on file to access my account???) ieven thou the key code is on.i never turned it on.and i have zero way of being able to have my key code send to me cell # nor email.i am really unhappy by this change.i didnt even get a notification of this new change.i think before ur yahoo account gets switched over with out u knowing i think its would be a good idea to have a pop up page with. all ur info on it. to update,add,delete. Info.anyways thats my option on the new app change. but if u could plz plz help help recover my email i would. highly appreciate it.i have important doctors documents.my sons school just went paperless and i have alot of school stuff saved and ect..... thank you sincerely yours,ms.jessica smith