As others have said. you need to keep meticulous records, but I won't hold out false hope - if you are correct that they want you gone, then it is very unlikely this will end any other way, so I would be doing a good amount of job searching.
Performance is often a difficult one to argue against, but I noticed that you said that you have been picked up on all sorts of things. So my question would be, is he right to have done so? Is there a performance issue to be addressed? Because the other side of the coin is that people do pass performance reviews - some of the time they are absolutely about what they are supposed to be about, which is identifying areas of work for improvement, identifying any help needed to get to that point, and achieving changes in performance.
If all that is irrelevant and you just want to leave, I wuld caution you to be realistic about your chances of getting much of a settlement. You haven't demonstrated any grounds here to suggest that they need to worry about you "having something on them", so they may be unwilling to offer much, if anything.
It's pretty much a waste of time and energy raising a grievance against a PIP, but if the manager has crossed any lines in showing the dislike you describe you may have some grounds there.
Sorry, that's all a bit generic, but without specifics it's hard to know what to suggest.