I don't have time to type out a long answer, so forgive me if this brief version comes off too harsh.

It seems like you haven't had a success yet with another startup, and a solid track record will, over time, be far more valuable than the 4% you're squabbling over.

Concentrate on making the company work (but also make it clear you don't intend to give up any more equity). Use this as a learning experience, and go into your next company stronger and wiser.

Given the very frail odds of success most startups have, it is likely not worth your time obsessing over this.