That sounds a lot like GURPS!
I guess I technically cut my teeth on MUSHes back in the 90s, but for tabletop RP it was definitely D&D and Vampire the Masquerade (which also spiraled into LARPing).
I TOO am the forever DM. But I love it, I have so so so many stories to tell. My previous campaign is the subject of Nanowrimo for me this year!