Failing Agency

There was a time that we were on top of the world.  Our agency was growing rapidly, our work was producing great results and there was a lot of external accolades.  Then it all started to fall apart, and it’s spiraling downward.  We lost a big client, made some bad hires and slowed down on acquiring new ones.
Just today I lost a bid on a potential client that’s half our normal minimum.  I feel like I’m going to lose my mind, and I have a client call to jump on in 30 minutes.  I’m actually afraid I’m going to get emotional on the call.  I’m out of resilience.  
I feel like it’s time to give up on the agency, but I honestly don’t know how.  It’s such a nasty spiral.  Less clients means less opportunity to market well.  We still have a few, but if we lose another one I don’t know how we’ll pay the bills.  
To add insult to injury I have a business partner that just isn’t pulling his weight.  He’s never been the greatest at self motivation, but I think the negative trend is made that even worse.  If he were a normal employee, I’d just terminate him and have some more breathing room, but as a partner that’s much harder.  I’m at a complete loss.
Does anyone have any suggestions?