No I was suggesting that if sessions are 'frequently cancelled' and is a reason you don't have much money that the upside of that is frequent opportunities for time to yourself for a bit whilst your child is at school.
5hrs a day max, five days a week term time only, with frequently cancelled sessions and a child in full time education is why you don't have any money to spend when you do have time off though, which is actually what the issue is.
I work full time (37 hrs pw) in a public sector job with a self employed partner who works 50 hour weeks 358 days a year (I make him have a week off for a family holiday in summer but he works evenings, weekends, bank holidays and Christmas Day). I've got two children a similar age to yours and very little unpaid childcare - the odd day from MIL in her 70s in school holidays. The rest is holiday clubs, breakfast club and after school club.
I still feel like I get loads of time to myself - I have an evening hobby outside the house 1 - 2 times a week with friends (something like a book club but more niche)- DP puts the children to bed those nights. A few times a week in spring and summer I get up early and go for a walk or a swim, or sometimes in the evening if everyone is settled and im not needed.
On Saturday mornings they have an hour of council run gymnastics (£4.50 a session) and I use the council gym/ swim at the same time. I'm currently mumsnetting drinking a glass of wine while they are tucked up in bed but if I wanted to be I could be out having a glass of wine with a friend instead whilst DP sits watching TV being a responsible adult in charge of a 6yo.
Just be realistic that it's money rather than time that's causing the issue. And you don't have money because you work very part time at the moment. You love your job and that's the choice you have made, but it does mean you can't afford the stuff you want.