I'm not sure that I can help - I hope the counselling does [but I've never had counselling].
I became depressed for a couple of years, about mid 2009 - mid 2011, and I can understand the 'I can't get motivated' point you mentioned: 'can't be bothered' was my feeling about almost everything when I was depressed, something which presumably arose because I lost the ability to 'enjoy anything' (either at the time, or 'in anticipation').
I can also say - because you said your partner didn't understand - that I used to have an aunt who suffered from depression. At the time, I couldn't understand it all - now that I've suffered from depression myself, I 'do understand it' (although I definitely would not recommend that anyone 'should become depressed in order to understand depression !).
I hope your depression 'lifts' faster than mine did, and I hope your partner understands that 'just snap out of it' isn't all that helpful,
Best wishes, Mike