Phone keeps freezing up everytime i open any app

My iphone 7 plus is acting really weird. Everytime I go to access an app it will open then close right back , then if I do get into the app, as soon as I touch something within the app my phone completely freezes . Ive restarted this phone a dozen times. Then when I restart it and it comes back on some of the apps have disappeared and I have to restart the phone again for them to reappear. I know i was low on storage so I deleted a lot of stuff out of my phone and it still says its full. I dont know what else to do , Dont have money to get new phone ugh help