Leaving job after 3 months, terrible?

I was at work for six years, tutored for a school year in college at the same time, went on to work for 2 years at the same company I did work through, I quit in September and started a new job that just.. phew. It’s been a doozy. My manager started in July and told me I’d get flexible timing, could work weekends to make up hours, had holidays (just unpaid), and I could work remotely when sick. She also let me know she was leaving the day that I started, then the assistant let me know she was leaving a month later. Manager seemed to lie to me to get me in to feel better about leaving herself.

I’ve been trudging and trying to make it work through annual reviews and open enrollment but Jesus it’s been a nightmare. I wasn’t allowed to meet my new potential manager upon her interviews so no clue what she’s like but she starts in two weeks. I feel terrible about the idea of screwing her over as she’s relocating. Big boss is weird, she goes back and forth from love bombing to yelling at me for stuff I’m not trained in or even remotely qualified to do (I’m doing the role as the director who quit as well as my job).

I have lined up a few opportunities, one is most possibly going to offer it to me as I know them. I feel like an ass though and I’m sick to my stomach over the possibility of leaving. I’d give adequate notice but ugh. I feel bad