It dawned on me that the most seemingly helpful people can be a hindrance when they start to meddle in your life, and give unrequested opinions or judgments.
Here’s a suggestion – practice re-framing other people’s negativity as a reminder of how not to be. The more negative they are, the more reminders of how pathetic that way of being is. Tell them gently, how non-supportive they are, and don’t judge or criticize them, because you’ll only be stooping to their level. Do it as diplomatically as possible.
If that doesn’t work, and their behavior is upsetting you, or you feel they are sucking all the energy from you, you may have to make a courageous decision about who you are, and how you want to live your life. That may mean surgically cutting them from your life. It may sound harsh, but do you really want to saddle yourself with people like that? Either they should move up, or you should move on.