I am so tired of this happening

It’s very possible I have a bug on my phone. I have reset my phone a number of times. It is okay for a little bit but my data this month is 100 GB. That is extremely high. When I look at my brave browser and what it’s used is 26 GB of regular data and 48 of background data which I have shut off. I also have an app that makes sure that the programs don’t run in the background so maybe somebody could tell me what the f? Literally twice the amount of background data. I don’t have a whole bunch of money so I can’t buy vpns and secret programs and stuff like that so maybe someone can recommend something that might work. Frankly I’m tired of resetting my phone and I do not understand. It also has something like ungodly amount of for unused apps. Is somebody hacking my phone and using my data? And if brave is so good why is this happening?