A couple of my good friends are real estate agents and they've said that some of the drawbacks are having to work at odd hours (ie on evenings and weekends) since that's when many prospective buyers are free to look at homes. The other big piece they mentioned is that the commission only structure of being a real estate agent (at least within the US) can be stressful. In both of their cases, they shared with me that if they aren't closing on a transaction within a given month, they still need to pay affiliation and "desk fees" to their agencies, but they aren't actually seeing any money from their efforts come in. Of course, that's something that you might be able to budget around, if you're able to gain insight into seasonal ebbs and flows of the business in your area, but definitely something worth considering.
Other than those two items, they've both shared that they really love the role! Good luck!!
I do not think there is a one size fits all of the negative mental effects of being an agent. For some people, that answer could be zero. It's all perspective.
Negative: Commision only means no steady paycheck
Positive: It also means unlimited earning potential. Not many jobs offer unlimited earning!!!
Negative: Can be stressful trying to get sales to close
Positive: The feeling when you do get that big sale to close is AMAZING!!
Negative: Talking to strangers about what you do can be intimidating
Positive: You get to meet and know so many different people from all walks of life.
My suggestion would be to flip the cup over and focus on the positive. Whether that's in real estate or in any other career as there will be pros and cons to any job!