Potentially sitting on a golden ticket I'm too scared to cash in... trade stability for start up?

Currently a 2nd year analyst in Corp Fin (FLDP but sitting in FP&A) at a >10B high growth tech company. Have had meaningful rotations, took the company through an IPO, strong relationships with leadership. I hate it though. I find most of the work to be meaningless (very little in the way of forecasting, a lot of analytics), sporadic (some weeks I feel like I work 30 hours, some 80+), underpaid (2yrs experience <90k in NY, ~110tc with equity), can't stand my manager whose running the finance department (ex banker from a sweatshop, treats us like it, no matter how hard I try we can't have any dynamic). And ultimately, I think high growth tech will suffer for a while in the public market and am already underwater on my equity. 

Recently got an offer from a series b/c tech company that wants me to come on and be their 2nd finance higher. I'd have a ton of "strategic" responsibility, own the operating model/KPI's/monthly reporting/etc., new boss seems nice, substantial pay increase with solid equity.

Seems nice, seems like a no brainer. But something in my gut is pushing me away despite most people saying do it

1. A lot of responsibility. I do very little in the way of core forecasting now and my team is >5 people excl me. I'm always "involved" with it but actually own very little. In this new job I'll be working with CRO pretty closely so in some ways don't feel ready (most everyone they interviewed had ~2 yrs of banking experience it sounds). New team only has one other guy currently so zero safety net
   1. Recently have been really feeling the imposter syndrome...
2. Closes the door of lateraling to banking due to age (23yo) (granted, with the deal/transaction numbers coming out this year maybe that's not bad?). I'm not necessarily desperate to be a banker, but do like the transactional nature and exits
3. Not sure I have a ton of conviction in the space. It's a relatively young/new space that has a few "bigger" public players with other large private co's getting ready to join the market too. Being at a smaller company it might get crushed
4. Hate my current boss, but he's best in class and great to learn from. 

I usually would be less apprehensive and more willing to take the risk. Maybe I'm just comfortable in my current job and need to break the mold? I get pretty beat down by my current manager which has not helped confidence