My computer sucks

Well, I can't watch anymore videos online or do anymore video calls because my computer is stupid. I have no fucking clue what's wrong. It just doesn't work. Every time I attempt to watch a video, it works for the first few seconds, and then it starts lagging like crazy. And whenever I try to video chat with anyone it works for the first few seconds and then I start swedishing. This doesn't happen on any of the other computers in my house, only mine. It's really fucking annoying. I've tried everything to fix it, and nothing works. I've posted on various places on the internet asking for help, and no one has any idea what the fuck is going on. I don't want to have to take it to the apple store and potentially get a new computer, but I may have to. FUCK EVERYTHING. Mehhh this really sucks I hate when my computer stops working. Welp, time to back up and schedule a genius bar appointment...merrr.