Previous Employer Harrassing by sending legal notice

Dear Sir/Mam, I had joined a IT company last year in March as fresher. Worked there till April 2023. Now I am in another company but the previous employer is harrising me by sending notice because of these reasons: 1. I did not complete 3 months period but only served for 2 months but I had informed & requested them to make it 2 months in resignation email only when notice period started because I was not on any client project or there was no knowledge transfer I had to do. I told them that I will pay money for 1 month notice period but they did not agree and approve notice period for 2 months since notice period started & during that time Harrassed me to revoke my resignation. so i decided to leave after 2 months with a final email to them to start new job. Now they are saying that I did not complete notice period so it is against law and I have to pay amount. 2. There was a 2 years employment bond with them. In my case i have to pay them 1 lakh since I left after 1 year. But I told them on resignation email itself that I will pay this money to them but no one responded to that email and now they are saying through legal notice that I did not want to pay and threatening me to clear that amount. 3. I have joined a competitor company which is using the same tool as they are working. They have mentioned in notice that I can't join that company or any company who is partnered with same tool..for 2 year but if I know only that tool then how I will get job if I don't work on tool according to them. They have mentioned as 15 lakhs of loss they have faced because I have joined competitor company but I did not share any confidential information or anything related to them in new company. I joined the previous company on 3.6LPA and they have asked me to pay 18 lakhs in total through legal notice. Is this even fair. Please help me. I belong to a very poor family and they are harrasing me.