My parent’s behaviour

I just want to get different opinions on one of my parents. We both struggle with mental health/health, the only difference is that they are way more outward and will tell anyone and everyone what they say is wrong with them. My role with my family generally falls as the responsible helpful one as the stereotypical older daughter. They only seem happy with my existence when I’m doing something for someone else. Anytime I visibly show that i’m struggling to this parent they either criticise my choices and life and bring me down by dismissing and invalidating me or they hit me with the “try being me, I have it worse.” They have always done since before I even hit the teen years. They just can’t or won’t provide comfort or show empathy, the conversation is either critical and hurtful or just turns into how much harder everything is for them. I just tell myself it’s because she does have a lot of children younger than me plus her own problems. But it does feel pretty bad being the seemingly very last priority to her.