As an extremely wealthy and powerful politician in the 21st century, Hillary lives in greater comfort than the overwhelming majority of people who have ever walked the face of this earth will ever experience. Her standard of living is exponentially greater than even many of the most decadent kings and pharoahs. She has a private jet. She has personal assistants. She doesn't have to worry about putting food on the table or providing for her family. She has the luxury, which most of us will never have, of wholeheartedly pursuing any dream she wants to pursue.
The main thing that frustrates Hillary Clinton isn't the rest of the world - it's Hillary Clinton. She wants power, and she cannot make herself stop wanting it. But neither can she bring herself to become the sort of person who people trust with power, who people want to give power to, and who will use it responsibly. Hillary is at fundamentally at odds with herself, and for this reason she is, I agree, a deeply unhappy person.
Simple example: Hillary Clinton does not support free college for everyone. This is something that most people want and most people expect her to support, precisely because most people think it is doable. But Hillary, for some reason, has it stuck in her head that this cannot be done, and so for that reason she refuses to support it. This is a source of enormous frustration for her because it's directly at odds with her goal of winning power; but she can't seem to choose which goal she wants to abandon.
Another example: Hillary Clinton will neither apologize nor repent for all kinds of past actions that have proven to be terrible and deeply unpopular. For instance, she refuses to denounce her support of "welfare reform", even though it was vociferously opposed by the left when she championed it, even though it has proven even less popular since then, and even though doubling-down on this is keeping her out of power. Clinton isn't entitled to our vote, of course, and it would be the easiest thing in the world for her to just do the right thing, particularly since it's the thing people want her to do; but once again, she is at odds with herself, and can't decide whether she hates being poor or not being president more.
Another example: Hillary Clinton insists on being a shill for Wall Street, even though this continues to endanger her path to the presidency. She has made herself vulnerable to attacks from the left, an odd decision particularly for a woman who needs to seize every advantage she can get if she wants to overcome patriarchy and win the presidency. Evidently, she wants to be a shill for Wall Street even more than she wants to be the president; there are of course worse problems to have, since most people will never have the chance to do either.
Oddly, a lot of Hillary Clinton's supporters, faced with the same dilemmas, are making the same mistake. They reach the fork in the road where they can either have bad, reactionary politics or win power by taking the good positions that people want to support - but instead of making a choice, they pick neither, and complain that they can't have both.
Of course, rationalizations for this sort of self-defeating behavior will become increasingly bizarre since they're necessarily untethered from reality. So for instance, you could take ownership of Clinton's decision to oppose single-payer health insurance, and accept that this is going to hurt her popularity and endanger her standing at the polls; but if that explanation's ideologically unacceptable to you, then you have to invent an alternative explanation out of whole cloth.
In that case, you'll do something like blame sexist internet memes for her failures. Or you'll blame sexist double-standards about the acceptability of unkempt hair. Then you'll have to accept all kinds of even crazier corollaries, like the idea that popular sexism among Democrats is what's keeping Clinton out of office. Obviously it's hilariously unlikely that things like memes and hair-styling conventions are what's keeping Clinton out of office, particularly since studies show that women actually have a slight popular advantage when running for office as a Democrat. But if you don't want to support good and popular policies, you have to come up with some alternative explanation for Clinton's problems at the polls.
It's understandable why Clinton supporters would be mad about all of this, particularly women who are accused of merely supporting her because she, too is a women. That's an obvious and unfair simplification; the truth is much worse. Clinton supporters generally support her because she is a woman and because they support her contemptible policies. They are enablers in this sense, the true source of her frustrations; they support her despite her unpopular positions and terrible behavior and keep pushing her towards the goal that she is actively working against - winning the presidency.
The irony here is that in the end Clinton will probably get to have it both ways after all. Our democracy is so profoundly broken, so rotten to the core, that no amount of self-sabotage is going to keep her out of power as long as she keeps working against the public will. It's an extraordinary gamble to live a life in conflicted misery with the hope that, one day, you'll overcome popular opposition to your terrible ideas and policies and make it to the White House; but it looks like that bet is about to pay off. When it does, perhaps Clinton and her supporters can be less mad and let everyone else have a turn.