I stand corrected. I thought I had some rights witin my family. Clearly not.
Ouch OP. When you're in a hole, stop digging. That is so manipulative!I
Of course you have rights in your family, but so does DH and while he seems to be respecting your rights in the relationship you don't seem to be respecting his. Being able to meet your family without the permission of your partner is a fundamental right in a healthy relationship.
If he was offered tickets on a weekend you'd already planned something then the response from DH to BIL is 'Sorry, that doesn't work for us, we're busy'.
Sending DH back with a list of demands for future arrangements including that he checks with you first is such an overreaction to a non-issue it's untrue.
I think you knew (and it was your intention) that after you did that the invites would drop off. BIL would have known full well that it wasn't worth even asking because you'd make DH's life a nightmare if he did.
I suspect the fuss over the discount is a similar effort - isolating him from those he is close to by making massive issues over small things.
And that last line, losing your temper and implying other posters have suggested you have no rights in your family and are expecting you to accept intolerable treatment - I would bet my bottom dollar you use that sort of manipulation if DH ever suggests a night out with his brother.
I'm not saying this to be unkind, but these are hugely destructive behaviour patterns. You need to think hard about this and deal with it - otherwise you will destroy all your relationships, not just with ILs and DH but with your DC too.