It sounds like you have junk on your tablet (virus, malware, adware, etc.) that is taking over. The only way I know of, short of running tons of different programs that may or may not work, would be to do a "Hard Reset" of the device. Just note that this will wipe any personal data off of it. So if you can safely take things like your photos, music, videos, etc. of of the tablet first (not apps), then I would do so.
NOTE: Doing this will clear 'all' the data on your tablet, so it is suggested you not choose this option unless you have to, or aren't worried about losing anything on the device.
Be sure you back up any data you want to keep, to a computer or cloud account, before doing the reset.
To "Hard Reset" the tablet...
1. Make...