To want to sell my half

[Verycold]

of a house I jointly own with my brother?

He won't have the means to buy me out.

My financial situation means that I need the money, is there any reason I shouldn't do it?

Sounds like a plan...

Still sell - if he's about to go through a messy divorce, you don't want his share of the house to become partly owned by soon to be ex SIL, so in the future if you want to sell you'd have 2 separate people to deal with, who might not be talking to each other. Get yourself separated financially from them before the shit hits the fan there!