How do you ask for help when you cant even identify what you need help with?

I feel like something is not right with me. I constantly have mood swings and mental breakdowns. I am always so easily irritated and sad. If i ever am happy than it only lasts that moment as soon as it stops i get back to being sad, but it's not always like that sometimes i just feel numb so i go on my phone and scroll on tiktok for hrs just to stop thinking for a moment. I hate this feeling but in a way it's comforting and i don't want it to go away.