Vim for Math Symbols

Learn tex (or better latex).

Even if you don't run it through tex to produce the output most people working in maths/physics will understand the tex statements for maths symbols in a plain text email.

There are a bunch of WYSIWYG tex editors, but with a bit of practice you can type it as fast as you could write the equations.

Stop banging on that screw with your hammer.

A better tool for the job is Lyx.

Or, since you're in school, you can probably get a really good deal on Mathematica, which is available for most every platform. They even have a version for just one school term, if you don't think you'll use it once you're done with this class.