I also felt sad at first. It seemed like a waste of time and energy. I felt a little lost like what do I believe now type thing. Now I'm able to look back and be grateful for some of the things I learned like showing love and kindness to all.
I've adopted some of the Buddhist principals like do no harm etc. I'm still a little bummed I'm not gonna live forever and sometimes wish I could un-learn ttatt when it comes to that but I can enjoy my life now. It gets better hang in there.