Get it all in, then cut it with a knife.
Are there synonyms that you can use that are shorter?
I found that there were many cases where I could combine two sentences with a semicolon and cut out a couple dozen characters. They add up.
I wrote three different personal statements. I really stressed over the first two, but could never fit everything in that i wanted. Then a few weeks before submitting I scrapped them both and started with a clean document. It ended up being about 10 characters too long, so a couple of minor fixes and it was perfect. Several proof-readers each made VERY minor corrections, and it was done. Everyone said that my last attempt was the best.
I think the process of writing the first two got the BS out of my system. The third one hit in a moment of pure inspiration. I was half asleep one night, woke up with an idea and was clear enough to write down the core of the idea before falling back to sleep. It was pure gold.
The essays that I threw out were not useless, I used themes from my original two PS to form the themes of my secondaries.
So I would say to finish writing the one you are working on. Get it cut down to close to the correct size, then pitch it. Use the lessons that you learned in editing the first one to write a new one. Use shorter words, better sentence structure, complex sentences, etc. then you won't feel like you must be so complete. The PS is not to show your whole life, just a slice of why you want to go to med school.
Good luck. There are several threads on how to write a good personal statement. Be sure to read them all.
dsoz