Take the job or pass?

I need advice! So long story short. I have a job that I really dislike, I don’t fit in with the crew, it’s a huge organization and their departments don’t communicate effectively. I had to go on medical leave and it was hell, I wasn’t paid for 2 months and they’ve treated me like anything but a valuable employee. I get paid 53,800 there. I just got a job offer making 58k and 70k by January. But their benefits aren’t as good as what I currently have but it’s a way smaller organization, and they offer a lot more flexibility for my kids. I have an autistic son and a daughter who needs a lot of different appts.

I’m scared to switch because of the benefits. Also, I get surgery soon and I’m not sure that my new job would be accommodating to my time I need off, but I really would hate to lose a good opportunity. I’m not sure what to do. Any advice? Do know that I am a single mom of 2 with no child support. So the pay does matter.