When nothing is going right, go left - leave it behind you and move on to something else. It's ok to quit something you can never succeed at.
Gambling is a waste of beer money - having a vice is ok, everyone has some flaw, but multiple vices will drastically increase the negativity in your life.
If you meet a person who will criticize you immediately and bluntly in a way that seems completely rude or offensive, keep that person close and never let them slip away. You will rarely find a person who cares about you that much. When you find someone who cares about you enough to tell you exactly how you do things wrong, make sure you appreciate that person.
When you complain about all the things that are going wrong in your life, 90% of people don't care and 10% are just happy it's not them.
If you ever catch yourself complaining "this always happens to me," that means you are doing something wrong.