An older man with a much younger woman is called lucky. An older woman with a much younger man is called a cougar, a cliché, or a woman having a crisis. The behaviour is identical; only the sex of the older person changed. That asymmetry is the clearest proof that most of what you are hearing is not analysis of your relationship — it is a cultural rule about who is allowed to desire and who is only allowed to be desired.
The rule is old and simple: women were valued for fertility and beauty, men for status and provision. A woman who wants pleasure, attention and love after the fertile years is breaking a rule nobody says out loud. That is why the comments are so personal — your appearance, your face, whether you are 'trying too hard', whether people will think you are his mother. Notice that almost none of it is about how he treats you, which is the only thing that actually determines whether a relationship is good.
Shame does real damage, because it makes you argue instead of assess. When you spend your energy defending the relationship to your sister, you have no energy left to look at it honestly yourself. Detoxing from shame is not about becoming defiant; it is about getting your judgement back. You are allowed to love without permission — and you still need clarity, which is what the rest of this programme is for.
One more thing worth naming: some of the loudest judgement comes from women. That is rarely cruelty. It is often envy dressed as concern, or fear from women who decided long ago that this chapter of their own life was closed. Their verdict on your life is really a verdict on their own.