My all time favorite affirmation is, "I am a worthwhile, loveable, and capable human being with 100% positive regard for myself and others at all times." Check out this hub for a starting point, and look at the featured books as well. https://hubpages.com/health/Thoughts-Feelings-and-... There are a lot of good workbooks available. You may need one more personalized for you based on what thoughts you are having that contribute to your depression and anxiety. Cognitive behavioral therapy might also help. Hope this helps mersaides. Oh, here's another hub that picks up where the above one leaves off
Here's a self assessment that might help.