I think I don't like the career path I chose because it's client oriented and now I don't know what to do, can you give me some advice?

In short, I'm a fitness instructor since some years ago. Mostly I work in hotels but I've also worked in gyms.

I've noticed this last months, after the last season, that I'm not sure if I like to work all the time with clients. If I have a bad day, feel like shit, or have any kind of personal problem I still need to smile a lot and be super nice with the guests. If they are idiots, I still need to pretend I like them.

It's especially hard with party-like activities like aqua-aerobics. I'm now in the middle of something like a stormy relationship and every time I have to go up the swimming pool and dance I feel like shit, pretending to be super happy and active when you only want to hide and cry is the worst.

I thought the problem was my current job but when I started scanning job vacancies I realized it will be the same in the same hotel or the same gym, always pretending to be happy and nice no matter how are you feeling today.

Right before becoming a fitness instructor I was a waiter, for most of my life, so it's not like I know another profession I can pursue back. It seems like if my strenght was dealing with people (which I think I'm pretty good at) I'm not good at any job that has nothing to do with clients.

I wonder if it was a mistake pursuing a career in fitness, it's been some years and I invested a lot of money in studying (right now I'm studyng a 500€ course on training). I feel I'm too young to "quit" but too old to change (I'm 34) and also I don't know if I'll find something as motivating as fitness. But also I don't want to keep going with this problem. I would like to find a position that has something to do with fitness but doesn't mean dealing with clients all the time, at least not at a level like a hotel.

I would thank you if you can give me some advice. Thanks.