Need help with depression

I'll try to keep it short. 

I've been struggling with depression for weeks on end now. I'm spiralling. 
Days pass by with me doing nothing, I'm barely capable to muster the motivation to shower. I'm self-isolating from friends, I feel like I have no one to talk to. I don't think I can discuss this with my gf, she won't understand. I'm just keeping up some appearances for her. 

I think I need a professional to talk to. Any pointers to whom / where would be highly appreciated.