I would look at this very pragmatically OP, if you do this for 5 years, you have nearly £1 million pounds, and or even three, and you could buy a house outright in the UK.
This will give you massively more flexibility and opportunities to spend with your child when they are over the age of three and can actually remember it!
Personally I found staying at home with one child a tiny bit dull and went back to work when they were around a year, but with a bit of flexibility in my hours.
I would see this as an amazing way to secure your future financially, which will free both you and your husband up so much in terms of offering quality time later on.
I think it's worth it, but you have to live with yourself. Two teachers, working full-time, will be exhausting, most of my teacher friends are either getting out or wish they could get out, the hours are long and hard at the moment in the UK. So, would you really prefer that lifestyle? Also, teachers cannot take just any time off they choose either, yes, long holidays, but you can't always go to children's events, school stuff as you are at school yourself.
I would grit your teeth for now, make the most of the time you have with your LO, and possibly think about reducing your husband's hours so there is one parent around more if you are worried about that.