Nah, second death is 100% not on you. Your post flair says you're playing second edition, so assuming you didn't have the Wounded condition then went you went to 0 hp they likely would've had at least one turn to stabilize you using any number of methods. If you had a Hero Point you could've spent it to stabilize yourself, even. I find it odd that they would've just merc'd a party member on account of a control effect that was placed on them.

As for the first death... well, that's more or less how a lot of us learn not to try taking on enemies by our lonesome. Pathfinder is a very teamwork-oriented game, so most encounters you'll want to have the whole team ready to face them. But that's one of those things that you kind of just learn with experience. Don't fret over it too much - there will certainly be more such lessons.