Rant - let down by family

Vent - I have a normally helpful family by my parent and the inlaws, however my parents in the last few months feel like they are out to make my life hard. We have wanted to knock down and rebuild for years and started looking at builders this year as we can finally afford to do it, they had previously said we could stay with them. Now it's a big issue and the offer has gone. Today I was confirming that mum could pick up my kids from school one day a week as previously agreed. I have not got other care, I have committed to working this day and booked and paid for a tutor for the term ($600) so today she says it can't be done, it's for 1 hr and the baby is at day care. I want to scream at her. Why today 1 week from when these plans are to start does she bail. I feel like she doesn't want me to earn the dollars to keep moving up. I feel like she is sabotaging me and I can't trust her to help even for 1 hr...... Crying is t helping just gutted she has done it 2 in months.