OP didn't feel the need to cancel their plans even after their partner begged them to stay.
OP tells the community that despite their partner having depression, they managed to make things work.
OP asked their partner to go with them and hangout. The SO backed out.
SO asked the OP to stay, but they sticked to their plan, making their partner upset.
What happened after the OP left has proven that they are in an unhealthy relationship.
With the way their partner reacted, the OP is considering couples therapy.
It's good that the OP recognizes that it's emotional blackmail and that they needed to stand their ground despite their partner's reaction.
The OP isn't a therapist, and their partner need to understand that.
Pushing the role of a shrink onto the OP is unfair.
One Redditor has seen this pattern so many times. She told the OP to run for the hills or things will get worse.
Sadly, therapy isn't working on the OP's partner. They still have to deal with their SO's problematic behavior.
The OP made a promise to their friends. They should keep their word.
Taking a step back from their partner is one way to process the situation and decide what happens after.
It's completely okay that the OP kept their word and hung out with their friends that night. Having depression doesn't excuse the SO from being controlling or dismissive of the OP's choices.
The partner needs to understand that couples should support each other through difficult times, but understanding boundaries and respecting individual decisions is crucial, even when one is dealing with depression.
What would you have done if you were in the OP's shoes?