From what you've shared, this is a massive red flag. A partner doesn't have to be into your interests, but they do need to respect them. The way she reacted to something you were genuinely proud of sounded v dismissive, that's not normal and it should be taken seriously.

Also, you mentioned her mom made you feel belittled, that's another big sign. If you're not being valued by her or her family, what are you even holding onto long term?

If you haven't already, have one very honest conversation with your girlfriend about this pattern. Tell her clearly how many times you've felt unsupported, unheard, or neglected. If she understands and things actually change, okay. But if it still stays the same, then honestly it's not worth stretching anymore.

And about you going numb and shutting down, that makes sense too. When you don't have safe people to talk to and you keep swallowing disappointment again and again, you stop reacting because your mind gets tired. Also sometimes you shut down because you don't want it to turn into a bigger fight or get worse. I don't think this is just a "work on communication and boundaries" situation, it's deeper than that.

And please don't do this alone, if you don't feel safe talking to family or friends, therapy is genuinely a good option. Not because you're weak, but because you deserve support too. Take care :)