How I deal with being mentally scared is unique to the nature of my scars and how I tick as a half-human.
Things I apply are:
1. Treating myself to good things even when I feel I don't deserve them.
---> For instance recently I made myself a lemon cake. Understand I usually make chocolate cake because my roommate detests lemon cake. This was an act of selfishness to make a whole cake for myself. It was good and I made certain to enjoy every lemony bite of it.... Well I did share with my dogs.
2. Meditation.
--> I stare at a candle flame and empty my head of thoughts and 'ground' myself mentally thus emotionally. There are many methods to meditate, finding one that works for you depends on you.
3. I don't 'should' all over myself.
--> Its the same as shitting on yourself. Depressed people get into the 'I should ______(fill in the blank)' mode. This is dangerous and leads to more depression. There is very little one 'should' be doing in life. Depressed people take 'should' to all new levels.
4. Reasonably pace myself.
--> I have a tendency to over do everything when depressed - from drink too much alcohol to throw myself into work to the point where I hurt myself physically. Moderating my activities becomes important to 'treating' my own brand of depression.
5. Allow scars to bleed occasionally.
---> I have scars, they will never actually heal so they are more like semi-open wounds. I have to find a balance between hiding those scars and allowing them to bleed. I allow myself some time in my life to focus on the 'shit' in my life and shed a few tears, or rage at the machines that made those scars.
I do this in constructive ways - ways I learned through therapy sessions with a lot of therapists.
6. I use my tools.
---> I went to many therapists (psychologists) and together we discovered what works best for me. Coping skills, dealing skills - figuring out a balance between allowing myself to bleed a little and either shutting down totally or hemorrhaging until I'm dead. The tools I have are for me. Finding your tools is a journey, there are may tools - however finding the ones that works best for you is largely trial and error.
7. List ten things that are good in the world in the morning.
---> For me I "down" on the whole world. Everything I see is dark and ugly. I make a list of ten things in my head each morning that make the world a prettier or better place. such as Roses, my gods, erm dogs, lemon cake.... Through the day I recall my list and allow myself to smile.
8. Defects of character I choose to keep.
--> We all have defects of character -issues/personality disorders. No one is perfect. I have worked on a lot of my 'crap' through the years and have changed a good deal about myself. However there are a few defects of character I choose to keep - they are part of who I am as a personality. They allow me to have my own unique take on life
Further more, since I know these are defects of character I can better regulate them. They are defects, most people don't like them - so I learn to temper those defects to the best of my ability so as to not sledge hammer everyone with them.
As for yourself - you need to dig down and figure out what ails you. I strongly suggest using a therapist to do so. A good therapist asks you 'how does that make you feel' and suggest different things to look at. They listen and ask the obvious questions helping you to ask those questions of self.
The tools I use mayn't work for you. There are a lot of tools out there, finding your set that works for you may be an interesting journey, but it is one well worth the trip.
Lastly - be good to you.
I tend to sign a lot of my missives with that - few people tend to be good to themselves. Learning how to do that makes life far, far easier.