It sucks, it's devastating, exhausting, and when you look at it day by day nothing seems to change. However, if you allow yourself to look at the bigger picture, after months, you DO seem to notice change in your life. But it's a very unsatisfying way of 'doing this' haha (in my opinion, idk how others think about that)
By having a negative attitude you are already preparing yourself for failure, and aren't surprised when you fail.
Being positive will, however, shift your mentality toward success - therefore increasing your chances on whatever you put your mind into. You will still fail, but I guarantee, you will fail less than being negative.