If Im happy something bad will happen to me or my loved ones

I used to have a problematic and traumatic teenage years. Isolated myself for most of my 20s , dropped school and found work to help my family. I am doing fine for the most part cause I almost forgot about the past but one day it suddenly creeped up on me. I am having false memories of the past and it breaks me piece by piece. Right now I am recovering a little but a lot of chances and good stuffs happening to me that it feels like something is going to happen. Everytime I do something fun or talk to friends there is these thoughts that tells me that they will know the real me and will leave me so I try my best to not show any kind of smile or enjoyment or anything. It also applies to anything as long as I feel a bit of relief and happiness. What do I do, I am so tired, I tried to improve everything about me but I still feel like the past is there to ruin me once again.