If you need treatment, you should get it. I was pretty severely depressed after Iraq (although I also have the PTSD thing going on they tell me, so that didn't help) and I'm really glad I got help. If it screws up your shot at the cop shop that would suck: but it's a real, physical problem and ignoring it won't make it go away.
One of my best friends has very bad post-partum depression. It took me forever to talk her repressed east coast ass into getting help, but as I told her "It's no different than getting cancer. It sucks a lot, but ignoring it makes it worse and ruins everything."
Whatever the consequences of treatment, they beat the hell out of the alternative. I'll also observe that hopelessness is kind of a symptom of depression, so consider that all the horrible things you can imagine happening as a result of trying to get help may not be as dire as they seem.