You are not a burden if you're living with constant anxiety. You are not a burden if your brain is programmed to think worst case scenario of every situation just so you're mentally prepared when stuff goes wrong. Truth is, you can be struggling and still be loved, still matter.
During childhood you could’ve been made to feel responsible for adults mood changes or you had to be on high alert for quick changes in behavior or patterns in order to feel/stay safe. So when someone’s mood changes abruptly this make cause you to feel like you’re in danger.