Teachers used to tell me this when I was little, but I don't hear it anymore.
But honestly, you can't expect people to follow through for you. There's only so much emotional labor that people can handle.
It's exhausting and stressful to have a friend who expects to be checked on like this. And it's depressing to talk to someone who always has problems. It's particularly bothersome to sane, normal people who feel happy more often than not. When they feel happy, they don't want to carry someone else's burdens and ruin their own days. No one likes that, not even fellow mentally ill people. It's less about you and more about them and their own tolerances.
Friends are just friends, they don't owe you a wellness check every week or a pity hangout every month. It's very likely that even if they did everything "right", you'd still be struggling. They simply aren't equipped with the means to fix your problems or help you cope with them. And mental illness doesn't care about how many friends are texting you or inviting you out to dinner. It will hurt you even if you have a whole team of people invested in your wellness. Of course a support system always helps, but you gotta make do with what you have.
It's important to have boundaries. Don't place this undue pressure on your friends. Even if you don't say it outright, people can usually sense when you are evaluating their every action and inaction. I think if they are even saying that stuff in the first place, they definitely have some kind of concern for you. There can be a million reasons why they never follow through. But that's for them to deal with. You just need to focus on yourself and what's best for your health. Enjoy their company when you have them around, and live your life when they aren't. Don't hope that your friends invest in you, because that means they will eventually need to cash out on your behalf. Invest in yourself, and aim to be capable of being happy independent from others. Otherwise you'll always be stuck in this loop of desiring attention, not being satisfied, and feeling worse as a result.