Yeah, your M1ATX is likely screwed. Honestly, I'm surprised your LCD isn't screwed, too.
The M-series PSUs are known to go up in smoke when you overload them. Search the forums for other members who have had the same or similar issues with theirs.
Should you get an M2ATX? That's up to you. There are other PSU options out there that, in my opinion are far superior to the M-series PSUs. I'm partial to the DSATX, but it's not the only fish in the proverbial pond.