Next time he does this (flips the script when you bring up an issue or something) just end the call / means of communication abruptly.

When he asks what happened, just straight up say “I wanted to talk to you about something with me, and you are turning my attempts to seek support from you into a focus instead on yourself. It doesn’t make me feel supported, and as that’s what I wanted from you, I figured the conversation wouldn’t help me.”

If he defends what he did with any “but you” then end that communication again, repeating the same reason if he asks.

Unless you give him consequences for when he does this, he won’t learn.

It’s okay to use our own experiences to empathise, but you should usually do some form of acknowledging the others experience first, and then making it clear why you’re about to offer your own analogy. Downright dismissing your experiences as “not as bad as mine” is actually a manipulative tactic often employed by gaslighters and the like (reversing the script and swapping who is the offender and who is the victim).