There may be certainly some times at which you do not deny the other person, thinking you may be hurting them. And this leads to make you think that 'Others often impose themselves on your wants & they are taking your advantage for just a mean purpose'.
While the fact which you always keep denying is:
Others being happy happy because of you drives you happy & taking this as reward you don't want to loose this feeling. But in the way of always being available to others at some point you are loosing your self-respect. Now, your priority has changed. You give happiness priority over self-respect.
Though this may cost you doing overtime, sleeping less disrupting plans still you do it just to get the pleasure of helping others.
Considering yourself dumb ..!
You are unhappy because you of thinking that ohers are doing better than you and icase you maybe happy if you would be performing better than others. A comparison may be intoduces just by seeing others. Now your, happiness index is decided by comparing with others. Now, it depends on with whom you are comparing yourself.
It's not comparing to others what hurts actually ; it's about the perception of one who compares, it is the thing which drowns you into sorrow feeling. You start to assume you are unhappy because of not having something which you should be having. These assumptions are made by your perception which doesn't even exist in real world.
Now, this results in loosing your focus & complete diversion of point of attention. Instead of focusing on yourself, now you start to copying others, following their lifestyles, copying sense of humor.