A slow startup and paying me merely 72k

I am not sure if it should be in compensation or careers. I work at a startup in the East Coast, this company started 10 years ago but recently picked up a little bit of pace, I have joined it a little more than 1 year ago and have seen the company getting it's first client, learned a lot and have seen many clients (it's a B2B security model), I am only developer, another dev. they had was the one who built the prototype and got shares in company and now works only remotely 10 hrs a month ( by effectively 0). I work under supervision of CTO and CEO, CTO is an ex prof. And very intelligent person and every day is new learning day because of him where as CEO is someone who is not technologically sound hence it's hard to work with, but I'm managing. Every other week I have to work roughly 10 hrs a day and sometimes I have to travel to represent our company on sales expo. I don't know why am I doing this, tried interviewing recently and Failed at a FAANG, completely lost motivation as I have a Master's Degree in CS. I am only 27 and my forehead has wrinkles, my hair's are greying and falling out and I am always stressed, Things have crossed limit last week as I couldn't sleep and I wake up with sweaty stressful nightmares asking you have a MS and you still can't earn enough to even pay off your student loan. My focus at work is going down because of constant headache. When I joined, I was told we are waiting for more funding, employee manual says appraisals happen in September, which is almost gone and have no news. I used to take work from home once or twice a month but CEO had bad experience with an old employee so she went ahead and changed the employee manual to state that work from home is counted only half a day. How to end this? I don't know what to ask you guys as I know I should keep leet coding ( with this crazy schedule ?) TC 72k, YoE 2y