Sounds difficult. I can't comment on being a parent and having a DH (who works) around. I don't think either of you are being unreasonable.
I'm a single parent working FT. I do understand the high costs of childcare though!! There was a point where I was paying out more than I was earning (and that was as a B5 nurse). I stuck with it though, as it allowed me to continue with NI contributions, pension and career progression. Since XH (who didn't bloody work and was unreliable with childcare) left , I also managed to re-jig my hours/shift times on my ward so that they would coincide with child care hours (but FT hours still). My youngest is 8, so I'll be doing these rejigged hours until she's starting secondary school (and able to get herself to/from school). It's been bloody hard though, but we're in a good routine now.
My bro and SIL have 2 young DC. They both work FT and have negotiated doing FT hours over 4 days. One does Mon - Thurs, the other Tues -Fri. They have a cleaner come in once a week. It means that they each have a FT wage coming in (along with career progression, pension contributions etc), but only have to pay for child care for 3 days a week. Would this be something that you/your DH could look at doing? My bro/SIL are both very hands on with the kids, and share out parenting/life admin/mental load equally. It's brilliant to see and works very well for them. Both my DB and my DSIL have time to socialise/do hobbies and they take that stuff in turns. It's what I wish my XH had done with me.
You said that you're planning to do your MW training. That sounds fab but I'll warn you now, that during placements, you will have to work shifts: this will be earlies, lates, long days and nights (and community/clinic). I can't comment on other MW units/L+D wards but ours tend to have shift patterns like this: 7am-3pm, 7am-8pm, 1pm -8pm, 7:30pm - 7:30am. In my area, there is no childcare that starts at 6:30am (to allow you to get to work for a 7am start). Nursing and MW training is a hard slog (I found it more difficult to juggle than my first BSc) and you'll need to have a really good support network around you so that you can attend lectures, placements and do assignments. Also, the placements can be anywhere in the area that your uni covers. I'm sure you know that but I wanted to say it. I retrained as a nurse when my eldest was 3: my folks were alive then so were amazing and helped me so much with childcare. I'd really recommend that you start researching what childcare is available in your area, and start planning how you and your DH will sort it.
I wish you all the best. Feel free to PM me if you want. I'm a B6 now, so the rejigged hours didn't stand in the way of promotion. Also my issues with XH, childcare etc have meant that I'm really understanding of just how hard things can be.