I talked about this in therapy and broke down in a fit of crying and yelling in the car to my mom when I expressed how I was feeling about this. Any time my friends or honestly anyone gets anything I don't have I'm immediately angry and fall into a pit of depression immediately after. 
It's like I turn inside out. 
 For example; my friend gets a job and I have to fake as hard as I can that I'm happy for her.
I can't be happy for people because my brain goes to immediately not being good enough and that puts me in the jealousy and envious mood. 
Also, nothing's ever enough for me. If something good happens to me it won't be enough, I probably won't appreciate it because it could've been better, I don't derserve it or there should've been more. 
This is a extremely toxic habit I have and it really fucks up relationships. 