Ok, so a few months ago I applied with one of the departments
in my area. When one of the detectives mentioned that if you
lie or don't disclose some information then you will never be
considered by this or any other department ever again.
This got me extremely paranoid.

For the screening portion of the process we were given a form
to fill out by ourselves.
Basically, I made a mistake and put on the form that I "used
inhalants" before in the past year. PLEASE NOTE: I have no
criminal record, I have a college degree, and have never used
drugs of any kind in my life. It's just that when I was mowing
a lawn this past summer, I smelled gasoline. On the screening
test, paranoia kicked in and I marked the use of inhalants because
I freaked out and didn't want to lie. Please also note that I never
had an intention of getting high when I smelled gasoline.

As you might expect, I got a letter saying that the department
does not want to consider me at this time, but I am encouraged
to reapply later.
One of the sergeants who has been helping me out with the process
told me to write a letter to the commander about the situation
so I can keep moving through the process and onto the
polygraph.

What worries me the most is what should I do now?
I would like to apply at other departments, but do you think I should
wait until all this gets cleared out? I mean I don't want to
apply to other departments so that they can see that this department
rejected me.

Any advice that you guys and gals can give me?

I doubt that will cause a problem. No one will reject you without an explanation from you, unless you failed a poly or something where they have a specific answer. Your application will be tossed in a few months and no one will know. Try to get that cleared up with the chief or something. They may just say omit that next time and toss your app.

If they can't, you are probably best to put that answer down on all preliminary apps to maintain consistency. I am sure everyone has smelled gasoline before but that is not something I would put down. Otherwise I would be putting down paint anytime I needed to paint a wall or a sharpie when I use it. I think too many people try to psych themselves out before a poly. Yes they want you to be honest but if you answer yes to every little thing in fear of deception, you will be labeled a criminal by the end of the poly.

Best of luck!