Negative thoughts - Repeating same thngs

My friend is facing issues with frequent negative thoughts. To overcome that negative thoughts she is doing things repeatedly  like washing hands again n again, dressing more time, whatever simple things doing in home. When she gets positive(herself) thoughts, she stopped doing that. She is doing this infront of only some peoples who she feels very comfort. If she face some new people or whom she fears...the problem not occur and say she can control doing repeated things...Negative thoughts about her grandma and some closed one died few years before..and she is having fear if the same happens for her closed ones in near future..What is this strange behavior amd how can we overcome this issue..Please anyone assist? Am from Madurai,tamilnadu. And am ready for video consultation if anyone helps..Thanks in Advance 🙏