It sounds like you've got two problems. First is that you are not respecting the limits of your tools due to impatience. A lot of working well involved working within the limits of your tools and materials. You may want to stop and think about that now and then. Second it sounds like you're trying to get die grinder performance out of a light duty 1/8 shank tool.

You could pay for one of the more costly Dremels and you'll find that they last longer. They make this stuff to a price point and you can't get $100+ performance and longevity from a $50 tool.

But having said that you still need to realize that any Dremel is a light duty tool. Even their good ones are not up to the sort of hard use that a Foredom or a die grinder will tolerate. Even the Foredom is more of a middle ground between the Dremel and a proper die grinder. If you're trying to dig and hog into the metal with either Dremels or Foredoms becuase you have little patience then you need to switch to a 1/4 inch die grinder that is either air or electric. An electric die grinder is like a Dremel on steroids. Most of them will stand up to heavy use that will cripple a Dremel in minutes. Then the Dremel or Foredom is used for the final lighter detailing and finishing.

But a decent electric die grinder isn't cheap. If you're complaining about the $50 Dremel because that's all you want to spend then you're sort of dead in the water already. Electric die grinders seem to start at around $130 for a Bosch unit I found online and go up to the mid $300 region.

It really is a question of money or time. Nothing you'll get from Dremel or anyone else for well under $100 is going to have a lot of resistance to hard, long term use fueled by impatience. But slow down, let the tool cool now and then and use it so that you're not dragging down the speed a lot and you can do the work with a $50 tool just fine. Your choice.