When friends cancel

[NewDayNewLife]

Hi everyone,
I would really appreciate some advice on a long-term issue I have been experiencing, which started pre-pandemic.
I am currently single. I feel sad and disappointed when my friends cancel plans, and when this happens it affects my mental health in the short-term. I think the reason I am disappointed is twofold: first, I can't spend time and hang out with them, and second, because I feel like I'm not really a priority in their life. I would feel better about it if they re-scheduled with a new date but this rarely happens. It happened again yesterday with someone who really seemed to want to come over, who then cancelled at the last minute and said they needed more sleep.
I believe the issue is with me, not them. As disappointed as I felt, the rational part of me was at least able to recognise that the person I was going to see yesterday likely needed the sleep and may not have had time to do so otherwise.
I would really like advice from others, if they have been in a similar situation and/or have coping strategies for dealing with this disappointment. I know that sitting around feeling sad is not very productive, but I have tried to busy myself with other activities and have found this doesn't work because it blocks rather than solves the issue.
Any advice appreciated. Thanks!

@Movingonup22 I read your thread about your situation and was really pissed off on your behalf! Glad things are working out well for you with your new dog walker friends

@Musttryharder2021 in fairness I think partnered up people who don't have any kind of hobbies or apparent life outside of their relationship are also boring and will have a hard time making/keeping friends, it's just they're less likely to want them (for now). The advice is directed to single people because they're usually who's asking.

Although I didn't see your thread, @MovingOnUp22, I'm sorry to hear you had a difficult experience.
I don't mind people mentioning hobbies. While I have lots of hobbies that I like to do on my own, I can definitely make more effort in finding group hobby activities I enjoy, especially if it turns out that the new church group ends up not staying together. And yes, I think single people are more likely to ask a question like this but that definitely isn't always the case.

Update:
Although this is definitely still a big issue in my life, I noticed something interesting today. A friend was going to call me, then suddenly said she got busy. At the time, I was busy myself (working on an assignment while waiting for her to call), so I found that while I was still mildly disappointed, I was much less upset. I am still trying to figure out which of my friends care the most, but at the same time, having a backup plan (i.e. starting the assignments) allowed me to focus less on the emotions of the situation. Hopefully I will remember this for next time...

@NewDayNewLife that's good, I'm sure you're right that being busy and preoccupied will tend to distract you from waiting for calls or texts, and make them seem less important too