Finances he takes care of everything.
Rather an an odd arrangement for a modern marriage, don't you think? Your earnings kept for a rainy day, your running away fund??? Perhaps your husband is concerned about money, whereas you don't seem unduly bothered, hence your ambivalence about returning to work.
Personally I don't think a woman undergoing chemotherapy is physically fit enough to undertake regular childcare, and handing the child over to aunts as and when is not going to provide stability for him.
Here's an idea. You pay the childcare costs, thus relieving your husband of a financial worry, and work two days instead of three, since 'saving the pennies' (you said) isn't important to you. You and the child spend the third day visiting the in-laws. They get to see the child during the day, not early evening, whilst you are able to supervise what happens; you keep your job, maintain your independence, and help the family finances, and your husband has no extra expense.
Thus everyone gets some of what they want.