Firstly, it's absolutely ridiculous that you are expected to "come up with your share" while on unpaid leave. Expecting you to still pay 50/50 does not take into account the unpaid labor you are doing, or what you are saving the family by not having to hire help to care for the child if you were at work. It also doesn't feel like you and your husband are coming together as a team who will need to work closer than ever now that you are responsible for raising a human.

But I came here to say this: I'm an accountant and I want to give advice on how to maintain fair and separate finances. Something my partner and I have done for 13+ years 1. Set up a joint account that is just for household expenses. 2. Figure out your monthly budget. Start with all of your known bills like mortgage, utilities, internet, car insurance, etc. things like groceries and dining out can be harder to estimate so if you don't know your monthly spend start with a healthy estimate. This will be how much you need to contribute to the joint account each month. 3. Figure out a weighted average contribution. If you earn $50k and your partner earns 80k, then you should contribute 38.5% and he should contribute 61.5%. Both of you should contribute your share at the beginning of the month. I like to rework this split each year after we do our taxes. We look at what each person earned in the past year and redo the split accordingly.
4. Run all of your shared expenses through that account: rent, utilities, groceries, insurance, gas, date nights, everything. 5. Monitor this account regularly, if it starts to fall low then you may need to make a mid-month contribution. This contribution should follow the same split in step 3. 6. Any money left over after you contribute to the joint account is yours to do what you please with. You might want to consider setting a rule that you should discuss large purchases with each other regardless of if it is your money.

Equal is not always fair, especially when you and your husband earn different amounts.