Extreme anxiety and bad thoughts

My daughter is 3 and my son is 4 months. I feel like I am absolutely losing my mind. My husband doesn’t get it. My 4 mo must be going through a regression or something he cries non stop all day for the past 4 days. Nothing I do calms him when he was the calmest baby before and slept sooo good. I can’t “sleep when he sleeps” this time around because I have a toddler obviously.

I literally can’t handle this. I’ve literally been having thoughts that I shouldn’t hAve had kids because I can’t handle this. I even had the thought of taking my own life just to get some peace and quiet. I feel like I’m slowly going insane.

He never stops crying. My toddler never stops throwing tantrums. I can’t do this anymore.

Can someone please help