Think the OP has had a pretty harsh time here - thought I was in AIBU for a moment! Im sure it does some peoples hearts good to shout 'get a job!' 'dont breed em if you cant feed em' but its not really practical or useful.
Ill state at the start that I am currently the single wage earner supporting our family, with DH taking on a SAHP role while he looks for work and failing that possibly retrains. So I know the stress of keeping it all going, while one person is at home.
From what has been said OP- you havent worked in 20 years, MH issues and anxiety, 4 children one breastfed, health issues which led to you going private and building up credit card debt, and DH who supports the family on one wage has suggested you get a job. From what youve said it also strikes me youve had little input into the family finances and decision making eg bills, shopping budget, and so havent really thought about how your personal spends fit in with that so they havent changed as the debt mounts up. You sound low in confidence, and in some ways that you might not be taking on a fully adult/partnership role with your DH eg not having the overview of the budget etc, possibly due to MH problems/anxiety etc
and perhaps its not just a case of 'get a job'' but change your role in the partnership with your DH? However these roles you are in have occured, its now an issue and hes asking for your help as a partner/to carry some of the load: and from what youve said hes been willing to help you when youve needed it over the years.
I think your idea about getting involved in the budget/utilities etc is a great one, it will help you in increasing your involvement and confidence and show him you are on the same page. Not a grudging 'Ill give up my treats' but taking on budgeting responsibility, the mental load of planning/shopping, decision making on the bigger things. Someone upthread suggested the boards on money saving expert or other sites where you make a statement of affairs and people can give advice on savings you might make - its surprising how helpful this can be as often we wander into financial problems through habit or inattention. Its also possible that something like this can help with some types of anxiety.
Might as well do this while you are planning for a job, but there is little point in work that doesn't pay more than childcare. Evenings, early mornings, weekends, or work from home are options but DH needs to be on board with childcare, and it may not come instantly, and geography limits things. Stockpicking, kitchen work, care work might be good MW jobs if you had somewhere near and getting into some work wont only help the budget but your confidence. But maybe a bigger plan: what do you want to be doing when that 10 month old goes to school? What qualifications and skills do you have?
Really hope you and your DH are able to work together to get through this, and good luck.