It doesn't matter if what you focus on is negative or positive, it will expand. Our subconscious mind is designed to find solutions for us and to verify things for us.
Have you ever been in a situation where you've tried to find a solution to a problem? You wracked your brain trying to consciously come up with a solution. But you only drew a blank. Then you let the problem go and you decided to not worry about it or to sleep on it.
What happened? Voila! A solution came to you. That was your subconscious mind finding a solution to your problem. Then can also happen when you seek God and the Holy Spirit provides you with a solution.
Your subconscious mind is designed to give you solutions to questions you have. When you focus on something, your subconscious mind goes into detective mode to find answers for you. It takes what you are focusing on and gives you a solution to a question you may have. It also finds reasons to agree with you, if you make statements.
For example, if you start your day and something negative happens, what do we often say? "I can see this isn't going to be a very good day" or something to that effect.
Then lo and behold, you'll have all kinds of things happening during the day to verify to you that you aren't having a good day.
Think about when you breathe. When you're breathing normally, there's no focus to your breath. You exhale and your breath comes out of your mouth and goes wherever the air currents want to take it. There's no direction and there's no focus.
But, if you blow air into a balloon. What happens? Your breath is focused toward the balloon. As you exhale more and more, the balloon expands. What you focus on, will expand.
When you focus on God, who He is, His love for you, His mercy, His power, His willingness to help you, strengthen you, be with you or give you solutions, those things will expand.
The same holds true if you focus on your anxieties , the things that cause you to worry or be anxious, obstacles or problems. Those things will expand too.
If you focus on your own abilities, with no need of God, this too will expand. This is true whether you are focusing on your perceived lack of abilities, small thoughts, your past or your regrets. These will expand.
Remember the following scripture and remember these will expand. "...whatever is true, what is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable...if anything is excellent or praiseworthy...think about such things" (Philippians 4:8)
Remember. Those things will expand.