I overthink every small things about people & conversations. Please help

Let me introduce myself first. My age is 31 years, working in an IT company and living in Bangalore with my husband. I want to share my problems on this forum as currently i am feeling the need of the same. Since my childhood, I was very shy person, always scared and less speaking.Gradually i overcame with this problem and transformed myself into an extrovert person. i can start communicating with any new person and can mingle easily. 

The problem with me is I overthink every small thing, specially about people, what they told me, old conversations etc. I take a lot of time to forget the saying of people. I take things personally very often in office and family. I feel uncomfortable when someone mocks me or do leg pulling in front of me, then i start thinking about that incident and it will take couple of days for me to forget that, even i try to spend a lot of time to think what should have been told in response or how to reply in those situations.Sometime i need to avoid the colleagues if they are too much of demanding or do a lot of leg pulling, then i had to stop interaction with them because it troubles me a lot , as i think a lot about them. 

Sometime i feel uneasiness in responding people if the question is not in my favour.I imagine the possible scenarios about each friend and relative, what question they can ask me and if i don't want to do that , what answer i should give for that ex: if someone would ask me for treat or party , what excuse i should give or if my friend want to become a partner in any business i would start, what i will say. those things haunts me by repeating continuously in my mind. Nowadays , negative thoughts coming frequently instead of positive ones.Mostly related to the relatives, siblings and office colleagues. 

I want to get rid of negativity but not able to overcome, tried every thing-- meditation, self help books etc. Sometime think about silly things which may not exist in future like what would i say if my sister want to to go out wit me as i dont like her company.My sister is in Delhi and i am in Bangalore, currently i am not having any plans to shift Delhi , i know that is not a future possibility still that thought keep coming in my mind. at night also, I feel it is difficult to sleep for initial half an hour as my mind keeps thinking something, 

I have to listen to some meditation or sleeping apps for sleeping. I have a lot of overthinking issues. I want to keep myself enjoy the present moment but not able to do that, always lost in some thoughts.Please tell me how to avoid unwanted thoughts.I want peace of mind without any noise. Also sometime I feel anxiety issues in office. I am having stage fear and public speaking also become difficult sometime.I feel nervous in front of a large group of people.My heart start pounding and voice becomes shaky many times. 

I hope you will help me after getting all those details.