The difference in a negative and positive man is simply how they view things. A positive man falls out of a tree and he says, "I'll be more careful in this tree." and goes back up. A negative man falls out of the same tree and says, "This tree is not for climbing." and walks away. The same thing happened but the interpretation is what made everything.
It is much easier to be negative and pessimistic in this world we live in. But I wager you this. There is no such thing as negativity. The first man will not fall out of the tree again. (Or if he does he will not fall in the same place.) The second man will not fall out of that tree again either. Both men simply changed their actions to prevent making the same mistake again. Both men simply reacted to preserve themselves. There is no negativity in that.
Look at your thoughts this way. The thoughts that say you'll fail. The thoughts that claim you're a loser. Are they really negative? Or are they just trying to prevent you from making some kind of mistake? Are they saying something in a way that you don't understand?
Ask the voice that calls you a loser why it says what it says. You'll often find it has a reason for doing so. It just found the worst way possible to express it to you. You have to dig deeper into your mind to find out why you've created these thoughts. And the most effective way to do that is by following "negative" patterns of thoughts and questioning them.
You'll often find that like a child your brain had good intentions behind the bad outcome it created.. And do we scold a child for not knowing how to express itself? Or do we teach them until they gradually get better?
As hard as it may be to accept this, there is no such thing as a "negative" thought.
The only "negative" that exists is the natural force that repels positivity. So why create negativity in our heads by becoming hostile towards our own thoughts?
So just for today, let us not repel the positive by labeling our thoughts as negative. And instead let's address them and ask why they are and how they came to be.
Shalom.