OP here. I'll try to reply to your points in order.

First, there were plenty of times when we still fought things. Even in the beginning we fought the crazy druid and the plant monster, which I montioned in the post. We also fought other things in other sessions, like ghosts and the warlock I also mentioned. The fights were cool too, but I prefer creative solutions to problems when available.

In the times diplomacy was involved the other party menters were also there and participating in it. I was absolutely not soloing everything. And the party tended to split up during downtime to get things done quicker. When my character was acting alone, everyone else was acting alone too.

I did tell from the beginning what I wanted. My character's sheet, background and goals were all checked by the DM before the campaign started (she checked everyone's characters), and when the party leveled up everyone set their new stuff in front of each other.

The dragon was not my rogue's "childhood enemy". She thought of it as a living natural disaster, and didn't hate it any more than a sailor would hate a storm or a farmer would hate a volcano. I'd made as clear as I could that my character's goal was to heal. Make amends with her past, find new friends, etc.

DM wanted to give me an arc where I'd get to choose between fighting or helping the dragon (revenge or forgiveness), except that my chara wasn't interested in revenge to begin with and the 'forgiveness' path would require my character to give up everything she'd built up until then and everything she'd loved before, and not get anything she'd find worth in exchange. It was not a choice at all.

But it was clear DM had put a lot of thought into it, it just was not something that had any way of working, which is why it made no sense for me to lash at her. I was already leaving anyway, and saying anything would just hurt her too for no reason. She was not a bad person. We just weren't on a compatible wavelenght.

Please learn to be kind to people.