It's kind of long, and over explaining almost always sounds like lying or self-importance.
"I'm good thanks, hope you are well. Sorry that I've had to cancel our last couple of dates. I'm realising I just can't make time for dating just now between completing my qualification and the kids. It's been really nice to meet you, but at this point I thought I better let you know where things stand for me at the moment. Take care."
Your longer message sounds a bit chaotic, emotionally strung out and with a lot of mixed messages. I don't think he'd be cringing, just more thinking it's all a bit much and kind of mind twisting.
'Hey, Hope you’re good! I have been thinking and I’ve enjoyed chatting with you and getting to know you a bit (you like him?) but I’m just so busy the now I just think there’s no point meeting up (no point? sounds kind of dramatic and defeatist). It’s not going to go anywhere, there’s so much time passed between our last date (my fault) and I just think it’s going to be like that due to how busy I am and probably won’t progress (are you being defeatist again or are you actually saying you don't see a future with him at all?) so don’t want to waste your time (are you being passive here, putting it in his court to choose to waste his time?). I have one day off a week the next couple of months (sounds kind of self important, I mean lots of us only have one day off a week in the long term, or none when you end up filling days off driving kids around, housework etc) and I really just feel like I need to be spending that with my kids and concentrating on them. Things will settle down for me around march once I qualify so who knows then (after all that you're hedging your bets -he might be good enough to fit your priorities in March?). But at the moment I just feel like I’m getting pulled in different directions (sounds kind of chaotic and passive) and I need to just concentrate on the kids and my placement and work before anything else. I’ll miss chatting with you though, have enjoyed it, you’re great and funny 😆 sorry just want to be upfront and stop wasting your time as I’ve cancelled past few meet ups (are you now flattering him, hoping that he'll call your bluff and say he doesn't feel his time has been wasted, and he'll wait?). X'
I don't know what I'd make of a message like that. I've got no emotional investment in it and, yet, I don't have a clue what you actually want. Too much, too confusing. People who don't really know what they want are best avoided. Maybe his mates will say some male version of "she's just not that into you" which is probably what it boils down to. In any case I think his response is absolutely appropriate rather than anything more drawn out.
I also kind of wonder if you're now second guessing yourself, not because of your friends comment but rather because of his brief response.
Perhaps you could ask yourself, what did you actually want him to say?
No one but you knows..
But if it was something like: "Sorry to hear that. I know you are really busy. Perhaps we could keep chatting by text and stay in touch, and see where things go. Take the pressure off now, and meet up in the future when things are a bit calmer in your life"
...then perhaps you could consider whether you could have communicated this more clearly. Lots of people on this thread say your message was mature, adult etc. I don't think so (sorry). Maturity is just expressing yourself with no games, no martyrdom, no emotional manipulation, passive aggressiveness etc etc . If you wanted a different answer, e.g. the answer above, you could have just asked, "I'm sorry I've cancelled the last couple of times. I'm a bit time poor at the moment with various demands. Could we keep in touch by text for a bit and see where things go, until I have a bit more time to focus on dating in the future?" A direct question asking for a direct answer, with no need for second guessing.