Need help, anons.

>Geotechnical engineer
>Feeling meh about my career; not quite what I expected it nor wanted it to be
>Money's decent

Should I go back and get a master's in a different field, like math, since I do enjoy the math side of things quite a bit (but I don't deal with it a lot in my practice).

Or should I maybe take some more structural engineering coursework, since structural engineering seems more interesting to me, and they seem to do more of the work that I want to do and with better pay.

Any suggestions?