I am naive. I trust people with too much.

Nah, you should've been able to trust them

Everyone commenting here is pretty spot-on, if you can take one lesson away, it's this:

Pick a good boss. Pick an adviser who fills that definition.

In a lab, they make or break everything. You can be an excellent scientist in a shitty lab... and you will end up with shitty results.

Don't get emotionally caught up in this project. It won't end well, even if you decide to stay. Good projects come from good labs, period. In a pressure cooker situation like a graduate program, any instability immediately produces cut-throats, because all of their asses on on the line, and there's not a strong hand there balancing out egos.

This quotidian Game of Thrones nonsense is all too common in some circles of academic environments because it can easily produce an unbridled ego and not place a high value on social grace. A good adviser knows this and nips it in the bud.

Kiss the professor's ass and get a good recommendation. Propose it in a way where there seems to be no other option but to leave, though you want to stay. Ask a professor you can trust that works in another department, or one who's not invested for the best way to do this. Look at other labs you want to transfer to, explain to them honestly your situation and impress them while showing a desire to work there. Thankfully you're not very far along, I've seen some grad students drop after a year or two to pursue something else and squander everyone's time and piss off the PI while they're at it. In the end, though, everyone was happier.

Science or man?

Pick yourself, homes. No one else in this situation is even considering that equation.