I know what you mean, I've had a lot of positive changes happen in my life, got a new job, a new cat...but my loneliness and self esteem issues consume me. I'm working on it through therapy, but I have said to her, I feel bad for feeling bad when i got so much going for me. I'm happy about the new opportunities, but I'm still not happy about other things, and so I get what you are feeling, happiness and then sadness.