I am working in MNC now in my role there are 2 kinds of contract small and big. At my level either people get 5 big contracts/20 small contracts/ mix of both.

I used to handle 3 big ones and 10 small ones.
We were a team of 6 people now recently one of my senior resigned from my team, so all his 20 small contracts were given to me not a single contract was given to my fellow team mates.

Now apart from that any contract big or small coming they are putting on me. So now in total i handle 5 big contracts and 38 small ones. 

I am an introvert please help. Not the best person when it comes to confront anyone or not the one who will question them.

Any tips???