Ask HN: Reduce my rate to gain more shares, but what should i propose?

I co-founded a startup, i am the tech guy and another one has idea + $$ + contacts. I was a freelancer and initially we arranged a hourly pay for about 25% less than i could get contracting, but thats fine for me. I got a 5% stake in the company for my reduced salary. 1 year down the road and a small investor giving 60k at a 1kk evaluation, we need more money to keep going and want to improve our numbers before raising a significant amount of money at a better evaluation. We have options, but also discussed increasing my stake and reducing my payment by 75% for 12 months, which would leave me at my bare minimum to live.. I believe in the company. how should i calculate the % i want to receive ? the exact amount of $$ which i am not getting after the cut vs the current evaluation of 1 mil, or should i aim higher ?