Forced to become a witness

My marriage was fixed with girl and no formal ceremony was done. 10 days before our marriage date, my marriage is cancelled after talking to that girl’s boyfriend. He provided me his personal bedroom photos with girl as proof. Afterwards that girl also confirmed me that her physical relationship with her boyfriend lasts until 20 days before our marriage date. Now her boyfriend is caught by police based on their FIR. FIR states that her boyfriend is responsible for breaking her marriage and circulated her personal bedroom photos to me. Now girl’s family want me to become witness against her boyfriend. My marriage is broken due to this accident just before 10 days of our marriage date. We faced financial losses, social embarrassment and wasted my one year due to this broken marriage. Now I don’t want to get involved in this matter further .I have following queries: 1) They are forcing me to become witness. What should I do? 2) If I keep silent, then what legal actions can be taken against me? 3) If I become witness what problem I have to face? 4) If I become witness then I heard I will not able to marry someone else till case is resolved, is it true? I will be thankful for your suggestions and advises.