But disregarding that, this thing is DOA.
• You haven't touched the market, have you done at least some sort of market study? (inb4; nope)
• One of the co-founders (you) is leaving.
• You and your "partner" are definitely not friends.
• Your product is an MVP in NextJS; is it also yet another OpenAI frontend? That has close to zero market value. (Although in the current environment you could raise a few million with that, lol. Note: you could raise != you could make.)
Because of all these reasons the chance of this making money irl is very slim.
What you both have to do is call it a day, stop fighting over literal pennies, end it up as gentlemen and then go on with your lives and find people that fit both of your desires and lifestyles more appropriately.