Everyone has bad spots in their life. Things like clearing out negative energy, a relaxing hot bath with some Epsom salt and a few drops of lavender oil, a few deep cleansing breaths, and even watching the sunrise or set, all help me during though times. Avoid alcohol, because its a depressant, and many people mistakingly turn to the bottle for answers only to find more problems.
"I don't see the purpose of being alive" scares me. If your suicidal please get some help. I only say this from experience. I too have thought life was hopeless, and even tried to end my life. I'm so glad I didn't succeed!
Life will get better!