Is it normal i feel like i'm the only mentally stable person in my life

These people sound like they don’t want to improve themselves or move past this. You should try to surround yourself with people who are thankful for what they have and are genuinely trying to overcome their problems.

You attract people on the same wavelength as yourself, so if you attract people you consider problematic you're the same way yourself wether you wanna see it or not or you simply have a shitty attitude which often people with mental illness do although there's exceptions. Serious anxiety and depression sound pretty serious to me, it's not exactly something that happens to everyone, and having experience with that you really should be more open minded and understanding. Maybe the fact that you aren't is even the reason for why you keep attracting these people and you will until you've found a better attitude and stopped looking down on them.
You sound like an old friend of mine. He was diagnosed with anxiety disorder and suffered greatly from it except when on meds yet one day he just decided he didn't have it anymore, stopped taking meds and developed this shitty bully attitude looking down upon anyone who showed the tiniest bit of weakness and pretending that his life was perfect even though from the outside it was obvious it was declining rapidly.