Sorry you are having difficulties. Let me just say that the idea that someone would hire a postdoc and then immediately try to make them leave, with no poor behavior on the part of the postdoc, does not happen. Either your PhD advisor did not make negative comments about you to Lab Y's PI, or that PI disregarded them and hired you anyway. They wouldn't do this and then try to make you leave. If the issue was really your current postdoc advisor thinking you initially wanted another lab, I don't see the big deal. Postdocs often consider multiple offers, especially good ones, and you clearly picked Lab Y. Also, if this was the case, you could just talk to Lab Y's PI and clear up the confusion. Something else is going on here. Do either the PhD advisor or your current postdoc advisor have problems with other students/postdocs?
Can I transfer my fellowship and be able to make a fresh start elsewhere without the interference of my former PIs? Should I just quit and forget about postdocs completely then go find something else. If I go for this third option what are my chances of ever getting a job anyway considering all 3 PIs are bound to give me bad references? Can I apply for jobs without my PhD advisers reference and can I exclude these last two?
Going to another job in academia without the support of your current postdoc advisor, and ideally your phd advisor, is going to be rough. You will need them as references. Are you able to give us more specifics about what is happening to you in Lab Y? Have you talked to your current postdoc advisor about things? Good luck.