I want to be happy, positive again!

Yes I keep smiling on bad days and forgiving people who take me for granted. No matter what lemons life throws me, life goes on. Everything I do, I consider others feelings but nobody does that to me. Maybe I'm wrong but it can't be all the time right? So sensitive now, I feel hurt even if it's just a rude reply that didn't mean it. I'm all but just human. I wish someone could help me get back to my happy, positive self again.