Keyboard got kinda messed up

Hello,
I've got some problems with my keyboard, exemple, when I want to delete a sentence, I've got to press the delete key for each letter, because for some reason when I hold it down for a quick delete, it won't work. the same for "space", it works okay while I'm writing but if I want to add a word in the middle of an already written sentence, it doesn't add space, it just brings me back to the end of the paragraph. Oh and on youtube (or any other videos with links on them) I can't click on the links in the videos (even if annotation in on) and when I press space, instead of pausing, the video just goes to the end. I have no idea what happened or what I pressed! I need help to bring everything back to normal!