This is incorrect. It strengthens both privacy and security in a lot of ways for an average user.

Your English is perfect. There is no indication of low intelligence from the way you described your issues. B and C grade are pretty average and indicates you can learn with hard work. I think what you might be experiencing is anxiety and that is causing you to think you don’t have skills or intelligence. I am not from US so I don’t know what kind of help might be available for you there, but I would suggest you to look for a job with something you like to do even though the pay might not be great and then eventually your interest will take you further in your career.