How others perceive me

I've always struggled with overthinking to the point where I form entire discussions and conversations between people that never even happened, and I feel like it's affecting my relationships and work life.For example if I'm in a group setting and I say something and see two of the people in my group conversing amongst themselves I automatically assume they're negatively talking about me and it drastically affects my mood and my readiness to be involved in any additional conversations or activities. I also struggle with one on one conversations with strangers/friends/family. I can't go out with my own mother without feeling a sense of anxiety where I stress about weather or not I'll have enough to say to her in order to hold a conversation. I also live with roommates who have been nothing but kind to me however if I ever catch a glimpse of them talking amongst themselves I feel as though I can hear what they're saying even if in reality I can't. Usually I imagine that they're having a conversation discussing all of the things I'm doing wrong and how much they hate me. Although I know none of this to be true. PLEASE HELP ME OVERCOME THIS! I work as a banker and my job requires me to be able to hold conversations with my clients and I fear that if I can't beat my anxiety I'll never grow further in my company.