I work for a small company. Will try to keep this brief. We are leading on a collaborative project with organisations from other sectors - we have worked with them before successfully. I am administrating. For reasons beyond our control the project had to begin at a bad time for everybody, lots of stressful juggling for all. I have been trying to complete the very technical contracts, which I have little experience with. I have made mistakes but done my best. We are trying to meet funding deadlines - signed contracts is one. One key collaborator is a freelancer, who is suddenly like a ticking bomb. They blame me/my company for every issue. We've had several ranting emails, a final one today has left me in tears. It's all my fault, i'm a time-waster, making the others jump ridiculous hoops, constantly making mistakes. They suggest the other collaborators feel the same way as them. Honestly, i don't know where to go from here, there is nothing I can say that won't be wrong, I have no idea how to respond to this in a way that will make a difference. A strong request has been made to them already by my boss who is on 'their level' to stay professional, clearly no impact made. My boss doesn't know what's got into them. I've never risen to the bait before but want to tell them to f*ck off and/or that I refuse to work with them. The latter sadly isn't possible [sigh]. There's going to be another year of this. Can anybody offer me better strategies? I'm at a loss