Yep - stick to the absolute character limit. If it goes beyond, it will get shortened automatically. If that happens & it appears incomplete -it won't get read. It will get tossed in the automatic reject pile because you didn't follow directions.
Now - how to fix it? Give it to an independent third party to read. You can use your mom or dad, but ONLY if they can be independent. All that stuff you put in there about going to camp when you were 7 and winning the best writer award in the 5th grade will be important to them. But, an independent reader will be able to tell you that is irrelevant "stuff" & needs to be cut. If they can be that objective, then they're a good resource. Otherwise, use a professor, a professional mentor of some kind - pharmacist, someone you know in business, etc..
Having said that, be prepared to totally rewrite your essay. You've gone off on a tangent somewhere & not kept to the heart of what they are looking for. So, don't get your feelings hurt. Just get a good "reader" who will look at it with critical eyes & be prepared for an extensive rewrite.
Always keep the actual question or statement the essay is supposed to focus on in front of you. Learn to keep asking yourself, is this relevant to the issue they are wanting me to explain?
Good luck!