What does Heather tell Melinda when she dissolves their relationship? How does it affect Melinda?

Heather has a lot of maturing to do. She is insensitive and ignorant to Metilda. Heather lashes out at Melinda's vulnerabilities,

'You don't like anything.You are the most depressed person I've ever met...you are no fun to be around and I think you need professional help.'

Melinda is shaken and crushed by this: she has a panic attack,

'my ribs are collapsing in on my lungs'