So for the past few nights my mind makes me think of loosing my family members. I can't control it..…

So for the past few nights my mind makes me think of loosing my family members. I can't control it.. I try to think about other things its like I won't let myself be happy because I then begin to think something bad will happen and ruin it if I get too happy. It's frustrating.. I can't take it anymore but I CANT STOP IT. Help 😔 This has happened before, but was never this bad...