I have the same problem as well! My handwriting is generally atrocious, because I'm usually trying to jot something down as quickly as possible. If I took the time to be neat, I could be.
My son skipped 1st grade, and he was already at the low end of the class for handwriting skills before the skip. His 2nd grade teacher would write things on his papers like, "I needed to get my 3D glasses out to read this." But he was lucky in that the teachers didn't press, they just said it would eventually come. And it did. My DS is now in 4th grade and his handwriting is legible. It's not the neatest in the class, but you can read it. His cursive is much better than his printing, probably because his pencil doesn't leave the page so much. We had worried about dysgraphia earlier, but I think it was more of a developmental thing for our kiddo (just turned 9).
He has some of the worst handwriting. I can tell him over and over to write neater and more legible but it really does no good because it always looks like a big jumbled mess when he is done with it. I can read it because he is my kid but sometimes I even have trouble.
I have the same problem.
It is kind of embarrassing when the law partner asks you what you wrote on the document when you are marking it up and you say "I'm not sure. My handwriting is kind of hard to read."
I can generally decipher what I was trying to say, though, so it's usually all good. Sometimes I have to guess, but I'm generally pretty good at reading my own writing.