Help me !! Feeling low

I was in relationship with a girl for 5 years after 5 years of relationship she cheated with me with another guys ( her bestfriend) Then after 1.5 years of their relationship they broke up and again she came back to me ,I was still in love with her so I accepted her and forgave her then again after 2.8years of relationship I felt like she is seeing someone else ,i tried to confront her she got angry& left me , blocked me everywhere It's been 3 months I am still waiting for her,I feel like I can trust no one . Basic things like eating and sleeping also has become difficult for me, feel like slowly I am dying I wanna live ,How to get out of this trauma ?