Make sure you are keeping your interest and blow the whistle.

This is a great opportunity. In most journals there are no guidelines regarding how a review should be written. You can simply summarize your comments about the paper, strength and witnesses, referring to the different parts (intro, method, results and discussion). Then consult with someone more senior and experienced (e.g., your supervisor)

Hey

This is part of science, and it will never end (even as a Professor, submitting papers and grants). You should take the comments you received and improve your work. Clearly, some negative comments can be personal and not constrictive. try to identify these and filter them out.

This seem most unfortunate.
My best advice is to look for some other place, and live. I know this is not always easy (relocating, starting new research allover again, and the "whispering" among colleagues as for why things didn't work out for you in your previous place).
You have no better choice. It seems you are surrounded by stupid people, which can be extremely dangerous, particularly in academia.