It sounds like you may have unrealistic expectations of people and those can get us into trouble. If you have a loving family and you still feel alone or misunderstood, then it might be time to talk to someone. There is this stigma about reaching out for help - but it's an act of self love. You may have a little bit of depression going on.
If you find people have been tuning you out, that's kind of a sign. And husbands are not always the best at listening to feelings. Mine would rather run the other way. Doesn't mean he doesn't love me. They just sometimes looked pained when we say "I'm not happy.". They like to fix things. But they don't always know how. Then they feel like they are letting you down. And they can't fix what's wrong inside you anyhow.
You might be going through some depression because of your mom's situation. I'm sorry to hear she's in hospice. That is very rough. Starting a new job .. being a mom, the kidfs being bullied - it's all hard. You need to look after yourself first, then dealing with what life throws you will be easier. Is there something you enjoy doing? Maybe take a class? exercise, walk, write in a journal, go out on a date with your husband (just for fun, no talking about emotions) ... and I would strongly suggest looking into finding a therapist. Just got for one session and see how you like it.
You remind me a bit of Zara - a lady who was writing in about her work experience, family and husband. Kind of similar as to feeling let down by her mentor, disappointed, feeling misunderstood. She got lots of good advice on here.
Sometimes the solution is within ourselves instead of thinking other people are letting us down. While you can't change people, the good news is you can change yourself. Let someone help you (therapy). Good luck :)