Advice on sticking it out through an unhappy working situation?

I am a newish (2 years out) grad, working in an industry that often gets mentioned on here. That part is a bit irrelevant to what I'm going through.

I am very lucky to be in the position I'm at. My small private company has stayed fairly stable throughout Covid19. My working hours aren't too bad at all (although I'm constantly on call). I like the company 'culture' for the most part, and the top leadership is both highly respected and fairly employee-centric. I see my current position as more of a stepping stone, but my company is fully aware of my ambitions, and they are supportive of them. They were going to give me quasi promotion, but it has been put on hold due to the global pandemic situation.

But...for the parts I'm struggling with

1) My current coworker, a "senior" with a lot of experience, is extremely difficult to work with. They are a nice enough person, but they completely micromanage everything I do in my job. They used to manage people directly, but HR got involved because she acted outright bullyish towards a few people. I feel like I can't do anything,in my job, because they want to dictate all the small decisions that get made. I have been here sitting idle at my desk for 3 hours, waiting for them to call me back on something simple. I don't want to stay in this department anyways, but it's abundantly clear that nobody will ever outgrow them in this little function. I would just say it's a huge morale killer - them always interfering in my work, and me having to say "Yes, that was very helpful. Thanks so much!"

2) I've outgrown my current job a bit. It's been 2 years in, essentially, the same title. Even my company was ready to move me along, but it is definitely on pause for the time being. It's just a combination of being sick of the same work over and over, and not feeling like I am learning. Plus, my job has never been something that I've been interested in as a career.

I'm just not that happy currently. It really feels like I'm just going through the motions. My motivation has sucked.

At the same time, I can't really do anything to change it. There's no way I can (or would want to) switch companies in this economy. As well, getting the role change I want is way more likely at the current shop.

How did you cope through fairly shitty management and general frustration?