I know how you feel with being fed up with being so sad all the time, but with depression (at least from my experence) it's definitely hard to say screw it and just be happy. It's easier said than done. I think it's a good start to have that kind of mindset that you have a desire to be happier. Some people are sometimes capable of pulling theirselves out of depression, and for some (like myself), can't do it on your own, and that is perfectly okay. I would suggest maybe talking to a therapist, a psychiatrist, or someone you love and trust, and then take it from there. I'm not sure if this was any help, but I truly wish you all the best