Trying to have a realistic, but positive, mentality helps a lot. Dark, bad, pessimistic thoughts are usually very toxic. Not that you can't be sad, angry, down or negative at times, of course. But when you can be positive, be positive.
Your unconscious mind will adept to your controlled thoughts over time.
i would suggest working out. definitly improves confidence in many aspects of life. it also lowers anxiety. Push ups are great there are many different kinds you can do if you cant get to a gym. or purchase a bench and some dum bells. wouldnt be to too expensive but putting your effort into weight lifting could be very therapuetic. Also listen to happy music and music that "gives" you energy like black eyed peas - anxiety gives me energy and strength to keep fighting. Also? i would find a good immersive video game to play to occupie yourself. i play so many different ones and it puts my mind at ease I dont know every ones situation but if you have someone close you can talk to then make an effort to talk to them, especially before your about to go out, this can "gear" you up in a sence for the upcoming events. I like to talk to my step dad before i go to work to kinda relax about socializing, and it really does help.. hmm i think comedy is amazing. ahh just hearing something funny as hell and letting go and being able to laugh makes me feel good about myself. it might sound odd but stare at yourself in the mirror. find things you like and try to just accept yourself. SA has a strange kind of hold on us where we think that our looks are really important to others happiness, so try and break that thought cuz truth be told. It isnt most of it is in your head. meditation has greatly improved my ability to refocus my thoughts and slip out of the anxiety and panic. Google search trancidental meditation if you are open minded enough. well good luck i hope something i said helps someone out there. i dont know you but i care, and i hope you truely believe that because i truely do..
Soak in what people tell you. Picture yourself putting their wisdom and advice into practice, before declining it. Then put it into practice (when you're ready to). Sometimes it takes some experience on your part to see how or why advice is good or not. Experience counts for more then people give it credit for.
And don't be afraid to get advice from someone, you're not obligated to do anything you don't want to. :3
I think sleeping well is very important. Like 7/8 hours a day and at normal times. Keeps your mind fresh. When you are tired negative thoughts come up sooner. Also having a good eating routine helps. 3 meals a day (breakfast, lunch and dinner) at regular times (try to eat healthy). And what Confusseddd suggested, excercise! Clears your mind and good for your body. Physical and mental health go hand in hand.
3 things that are easy to do and can make a huge difference. You dont have to expose yourself to difficult situations, but you will notice that after a week you will be less negative and more fit to fight your anxiety. I guarantee
Depression: Get out into the Sunshine and go walking. Doesn't matter where, wherever you are most comfortable. This can be beach, bush, rivers, parks etc.
SA: Find people who have made a success of their life / have a positive attitude and talk to them. Small talk is made by people who are "small". Those that have achieved more, will quite often speak more intelligenty than those who have not achieved much.