phone problems

so I broke my phone a year ago like in 2015. i cracked the iphone screeen. i got it fix and okay like couple months later at the mall. for 100 bucks. now it’s been a year and now the screen is falling off like my phone is done already giving up and falling apart idk what to do because i don’t have any money to buy another phone . my phone is Iphone 6 and it’s very expensive . what should i do 😰😭. should i sell this phone and get another phone ? or no one will buy this phone i have? It actually works good.. just the screen is falling offf and also it has bubbles on the screen too like when you get it wet and the bubbles on the side of the screen .. How much will this phone be worth if i sell it???