I read Matthew 6 and the pressing impression I left with was that I need to focus on myself and really only worry about what God tells me, not what the world tells me. My motivation for whatever I do should be to serve God. If that is what I am focused on, I will not be worrying about what others think. In fact, in Matthew 6, Jesus clearly states that you are not to do things to be seen by others like giving, praying, fasting, etc. The motivation for such things should not be earthly glory by others or praise from others. In fact, Jesus is clear that if that is what we are looking for, it will be our only reward. The motivation should be to serve and honor God and when that is your motivation, you don't need anyone else to see.
If your focus is on God, worry should not be a part of your life. It does not matter what others think. I heard Steve Chiles once say that "worry is really praying to yourself." When you worry, you are focused on what you can do or not do about something in your own strength. None of us has strength enough to handle all of life by ourselves. The good news is God can and will. All we have to do is trust Him and wait to see what amazing things he has in store.