It's important to get some facts first and not work off of your assumptions. No matter how strongly you sense that you're "getting the cold shoulder from everyone else", it could just be intesified by your emotions.

Schedule a 1:1 with you manager. Don't reveal the agenda, but be polite and just say you want to discuss some things.

During the meeting get the answers to your questions. This time you can be direct (but still polite). If your manager is beating around the bush / sugar coating, your initial senses were probably right.