Depressed and relationship confusion?

[Kitten]

okay, So I'm very depressed about everything in life. Nothing feels the same, every thing I see, touch, do lacks in any kind of beauty and nothing brings much enjoyment to me. I. Feel. Nothing, But sad, I miss the hell out of my girlfriend that I now have no attraction to whatsoever almost. It's kinda like she annoys me, but not in that way, I still call her all day and blow her phone up with texts. I still lurk her Twitter and think about her constantly,BUT, When I do think about her, I feel as though, I've lost feelings for her. I don't see/have much enjoyment with her company. I don't feeel the same but it hurts when I think about what we use to have. I miss it all and want it all back.. I know deep down I love her, but I just don't even wanna hang out with her.

Now the question here is,

Is it possible that Depression can cause relationship problems, such as, lost of interest in partner, emotionally?

Also is that necessarily permanent?
Will I never be able to care for her again like I used to, or (if the depression did cause the lost of connection) is it gone forever?

I don't wanna lose these feelings, I don't wanna lose this girl. Help me please.

[MM]

Depression can absolutely hurt your relationships with other people, including loved ones and family. It doesn't have to be permanent, but you stand a much better chance of fighting it if you get professional help, like you would with any other illness. You should also let the people you care about know what's going on, so they can support you or at least be alert for when it's affecting you.

[Twisttee]

Yes, depression can be causing the problems.
No, it doesn't HAVE to be permanent.
Tell her what's going on (being depressed, not that you've lost interest)... and seek professional help.