Another couple of quick suggestions:

When your mind starts down the negative path, and you realize this - simply say "Cancel, Cancel".

Then, to get it back on track to where you'd like it go to, ask it a positive-based question - and relax. You may not get the answers immediately, but the asking puts it into a positive "frame", so it needs to look for positive solutions for you. Simple questions such as 'How can I acquire "X"?('x' being whatever it is you do want in your life - health, freedom, personal growth, money, etc.). You may not get an answer immediately, but you can also then move forward to visualize/imagine (therefore, showing your mind) what it IS that you do want - and it'll put out a cosmic search team for you - to find IT. Keep asking these types of questions whenever you catch yourself heading down the negative-talk path.

Then start paying attention to things happening in your life - being alert to opportunities when they do show up is better than half the game. That's the big difference, actually, because as long as you allow your mind to preach all the negative it's been fed by others (creating doubt) in your life, you'll not be focused enough to see opportunity when it arrives. Learning to focus is a skill easiest acquired by doing some form of meditation daily, even if it's only 10 minutes per day. Learn how to turn on the switch of the laser light in your mind, and you can shine it wherever YOU chose it to shine.

So, ready - set - FOCUS!!!

Cheers!
Unis