Need to know if there is any help i can get as an employee

Hello, I was an employee of an IT company. When they hired me they had given many fake promises such as I will be 10% partner of the company. I will be earning certain amount per month, etc. However, I trusted the words and all these were never taken in writing by my side. They also made me sign a contract (not stamped, it was on company's letterhead) which says i can't do any freelancing work. I had refused to sign the contract, but they they explained this is just a formality and this is the same contract we have common for all. So I had signed it. They made me work above and beyond my designated job role which I did with full dedication and excellent performance. However, they were not getting satisfied and keep on torturing me to do more and showing me I'm not worth it. Still I kept on working with a hope that one day they will be please, but it never happened. After almost 3 years of suffering, I started doing part time freelancing and to get projects I opened a website. However, I never got projects from website. After a few months my owners get to know that I've opened a website and they terminated me because of this without giving any notice period. Still I completed the process of hand over to them by giving all details and information. At that time, they told me they will think and let me know the decision for my salary and experience letter of 4 years I served the company. Even they said they wish to give me freelance project of the company. After so many followups in email, my HR called me and said, "The company has decided to not give you salary and experience letter. You can consider as settlement as we haven't filed case on you for ceasing contract by doing freelancing". I asked them to give this in email, but they refused and never responded back. I decided to move on and as I didn't have experience letter, I couldn't get job. I started business and reopened the website because of which I had lost my job. Now, the owners of the company are sending verbal threats to me that if I won't get that website down then they will sue me and spoil my life. I'm feeling so depressed that I can't mention. I have following questions: 1. Is a simple letterhead contract is legal to abide an employee or can it be used to file a case? 2. Is it a crime (cyber crime) of doing freelancing by ceasing the contract term which says we can't take freelance project? 3. Can't I do anything to get my last month salary and experience letter? (they made me work till last day of month even if they get to know about site before 15 days) 4. It's been 2 months, they fired me, still can they sue me for the reason of ceasing contract when I was an employee? If yes, then till how much duration they can threaten me? Till end of my life? As this is not only about a website. they may keep on threatening me till uncertain time. 5. Is there any law for me as an employee which can protect me from all these? or do I need to live rest of my life in threat that any time they can sue me? or ask me to shut off my business? 6. What is the punishment as per law for ceasing this rule of doing freelancing even if not allowed as per company's contract? 7. Is there anything which I can do for finishing this matter with help of law so can live rest of my life peacefully? (Settling down it with bosses is not an option as they are uncooperative and seems they want to keep this as weapon for unknown reason to bother me as and when they feel to) Please be noted, I never stole data of the company, never contacted any client of that company. What I did was on my own. Seeking for some solution to get rid of this stressful threats. Thanks