In need of moral support

So this evening my partner found out that his business (currently run and managed by himself, but his brother has shares) is failing. His brother told him to start looking for a job, had loads of personal digs at him and has majorly put him down.

My partner is now adamant that that’s the end of their friendship. His brother means nothing to him. He set him up to fail.

This is where it gets complex. I have an amazing relationship with his brothers wife, I get on so well with all of his family.

My partner is shutting himself off, and by doing so, essentially shutting me off from his family. He says ‘you do what you want!’ Which isn’t fair on me or anyone else in the situation. Family means the world to me and I can’t stand to see him tear his apart!

Any advice or just moral support would be helpful. I’ve taken myself to bed so I can cry alone.