I also find the comments here pretty weird, especially those along the lines of I HAV WAY MORE FILEZ AND IM OK. I mean, seriously kids.
A few things. First, commercial law is a high stress profession and burnout is everywhere. I don't know anyone who's been in the profession for more than a few years who hasn't experienced it in some measure. Learning to manage stress and recognise burnout is an essential skill if you want to last long.
Second, without being an expert on burnout (other than through experience) it's not typically the work load per se that is the problem. The first few years are hard but you get used to it - routine is everything. It's more about being in an environment where the gap between your responsibilities and capabilities is too great That gap narrows somewhat as you become more senior. It takes about 2 years in most jobs to get a sense of what is really going on so I'd encourage you to stick that period out if you can.
Third, commercial law is a large field and you're just at the start of it. What aspect of your current role is most stressful? If you don't like being a glorified process administrator, don't work in a volume practice. If you don't like unsociable hours and silly stress, avoid deals. If you don't want to spend many hours thinking about academic points of law, avoid competition. If you aren't a masochist, avoid tax. And so on. Different teams, firms and practice areas are so different that you should try not to form a judgement about whether commercial law is for you until you've had more experience.