Strange feeling

Hello all,
I come to this forum after reading around and seeing that other people out there have some of the exact feelings that I do. I usually dont open myself up like this, but it almost feels better to get these things off of my chest.
Lately I just have been feeling strange, not myself, and lost. I really in the grand scheme of things realize that I have nothing to complain about, or feel bad about, or feel sorry for myself. I have a great job, a family that loves me, and friends that I know must care. But alot of the time lately I feel exactly the opposite.
I feel as though I hate my job, a job that I have worked for a long time to get, and used to be so excited to go to that I would stay up all night due to excitement. Now I find it hard to drag myself out of bed in the mornings. My day to day job is as a firefighter/EMT and I work around alot of people, and feel stupid for feeling the way that I do. I see the people out there that have been diagnosed with depression and I think to myself that I would NEVER end up like them, but lately I just cant help it. When people think of firefighters they think of big strong people who are immune to life and have nerves of steel, but it could be that my job has finally gotten to me, the horrible things I have seen and done.
I also know that my family loves me unconditionally and I know this because they show me every day. But there are times when I just feel like no one cares about me, which again i know is bogus, but i just cant shake that feeling no matter how hard I try. I dont know why I feel this way, but I guess I just DO.
Finally I have alot of great friends, people that I know care too, but lately I feel like its just hard to be around them, as though either I or they have changed and we no longer mesh. I just dont like them to tell the truth. I feel like its hard to be with them, and that they arent my friends, they are just some people.
I have no idea what to do, I feel like I cannot let people see how I truly feel because of my job and feel like it could ruin my career. I also just dont have the will power anymore to fight this, I am constantly tired after doing almost nothing, I dont have interest in any of the activities I used to once love. I dont necessarily feel like harming myself, but I dont think that I would put up much of a fight if its what it came down to. I feel alone alot of the time, and have never really had a serious relationship, nothing ever seems to progress. Its like I am on a merry go round, just spin round and round in the same place doing the same thing.
In any case I appreciate anything that people have to say, and it just makes me feel a little better putting this all out there, even if it means relatively little.

thanks.

Depression isn't something that discriminates between people in how good their life is, how lucky they are, how hard they are working. It's just a crappy disorder that grabs random people and messes with them. You're not stupid. This isn't random complaining or feeling sorry for yourself. It's depression.

Depression, I am reliably informed, is a lying SOB. It will lie to you about people not caring about you, about your right to talk about this with friends, about whether you deserve to feel this way or not. It's the toughest thing in the world to NOT listen to it and to reach out for help. Seriously, tougher than your dayjob, and I can only imagine how tough that is! It's what you need to do, though. This isn't permanent. You're not broken or messed up. You're still you, just with a layer of grey over the top. Time to get some support. If there's a counselling service available via work, that's a good choice because they'll understand the issues straight away. And if there is, that proves that they must be needed. That service wouldn't be around only waiting for the one person who feels this way.

If there's not anything like that, or if you aren't comfortable talking to them, then please talk to your doctor and go from there. It can get much better than this. I hope it does soon! Keep posting, if it's helpful. Lots of people here feel similarly, even if they don't always know what to write.