Hi everyone,
I have done almost 500+ questions on leetcode. I am a tier-1 college final year student with majors in non-circuital branches (biotech ,chemical, mech etc).
Only few companies are open for these branches. So, it means less chances to even sit for these companies and gain experience(be it good or bad).

The main issue is that for companies that are including these branches, for that I am not able to clear the online coding round(which include aptitude, OOPS, CS fundamental concepts, 2 to 3 coding questions (combinations or somtimes only coding questions)) . So, I am not getting selected for further rounds. This is taking a toll on my confidence and I feel extremely low.

I saw a few people being vocal with their issues. So, I thought of speaking my heart out and seeking help from you all like minded people.
It will be of much help, if this amazing leetcode community can help answer my queries which are:

1. Can someone tell me where am I going wrong ?
2. How can I improve my performance ?
3. What exactly should I do to clear these online rounds?
4. Can someone tell me from where should I study OOPS java concepts?
5. What to do when you feel drained and low in confidence?
6. For CS fundamentals, where should I study them. I kinda find myself anxious and lost when I try to 
prepare these subjects.

Thanking you all in advance. I hope to get a direction after this.