Sometimes depression can reflect a unique and valuable reality other than the "life sucks mentality" and sometimes depression is just depression. Look hard and see if there is more than meets the mind and your eyes may see something entirely different for a change.
Always seek professional help if you have an issue with depression.
It takes time to fight for justice and the things you believe in (such as humanity) so make sure you pick your fights carefully as they will eat up your time faster than a wildfire spreading throughout the summer.
No matter how strong the desire to do something that could tamper with your quality time (and that's all you have) is, focus instead on new strategies that enable you to get what you want without making the same mistake twice.