Nervis1,
Do I understand that it is the cutout that is letting loose and jamming to break your tool? If so, the solution is to rough out all the material so that there is no chunk to contend with. Either that, or you have to figure out a way to secure the cutout so that it cannot move as the last "tab" is cut through.
I don't know how long the 1/8" carbide is, but IMO, they are generally too long to last when doing a full diameter cut. I usually shorten them up so that there is only a 1/4 inch of useful flute length. Then, they seem to be stiff enough to do some cutting for a while.
I cut the tool off with diamond wheel and then regrind some end clearance on the tool's end.
You might also consider trying a HSS cutter. You cannot run it nearly as fast, and it should be flooded for cutting, but HSS is tough stuff compared to carbide.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)