You're probably right that you need to defer just now but bear in mind that a toddler will still need someone around who can lift them in an emergency situation even at three. Probably a good idea until your toddler can do things like get into a highchair alone, yes, but at that stage you may well find the nappy changing wrestle is more than this op can bear.
I've been very unwell for two years, with some operations. I have two DCs now 2.9 and 5.2. You will need to find some way round it in the end. I think you need to be more realistic about arranging and accepting help rather than hoping that you don't actually need it! Harsh, but ... .
When I say relatives or friends I don't mean one person for two or three weeks, I mean a rolling programme of people who are there to help. If your DH is an employee he is entitled to statutory holiday and statutory (unpaid) paternity leave. You may have to consider using these.
At one point I had my mum down for one week, a rota of friends every morning for the next three weeks, my sisters (who both have DCs and live in different places) covered weekends, my dad for another week. It's hard, it's a pain, but you can juggle up something if you need to.
The nurses talked to me of a fabled au-pair who lived in for £60 a week. I didn't find her but I did end up getting some paid help, with some help from my dad. You can get temporary nannies and mother's helps from agencies, although you are probably looking at £8 plus per hour, depending on where you live.
I didn't have this op, btw, but another where I wasn't to lift. I didn't lift and I still have a nearly-hernia which will eventually herniate.