How can I stop arguing with myself in my mind?

You can't. Second-guessing and even arguing with yourself is a normal thing - the key is to not let it get in the way of your day-to-day activities. Ask yourself why you're arguing, and if the point of your arguments is truly something to dwell on - once you've resolved the issue internally, you can start solving things externally.

Find peace, find God, you will feel incredible, I promise! Believe in yourself and just think you can do and be whatever you want!

You need to forgive yourself. Living in peace with your mind is the most important thing in your life, believe me. I forgave myself everything, and now I'm happy

Don't try. Right!! No matter how absurd this idea seem to be but the best way to quite a mind is to let it be. A mind is like a muddy water in a vessel. If you would try to force it settling down the mud will keep floating at the top. However, if you would let it be the water will quite and the mud will start settling down at the bottom of the vessel. Most of the times the best solution is to let the situation be as it is. I think there is a beauty in not trying.

Try to relax. Take deep breaths and find an outlet to distract yourself with. Something like music or drawing can make a difference between running circles in your mind and being able to move past it.

By letting go of what is bringing you down. It seems like a never ending pattern of constantly telling yourself that today is the last day you will do it but then the next day you do it again and again and AGAIN. Stop tricking yourself into thinking that something good can come out of a situation when in reality that situation is bringing you down every day.

It's usually a good idea to find some kind of distraction - going for a long walk, or to the gym (physical activity is really good, and helps you feel more positive too)!

Ignore yourself, or, if that's too hard, speak positive thoughts and sooner than later, those thoughts will give up and go away, not to say they won't always be here, but let positivity and goodness defeat all bad.

I don't know how to really answer this one, as I have battled with this for most of my life thus far. I do know that when I have meditated, it really helps to cease the mental battlefield. Also, positive affirmations tend to help the mental chatter as well.

That is tough, but activities that help practice mindfulness is usually a way to get our brains in gear. Yoga, meditation, exercise are all really great ways to do that. There are tons of resources online to get connected without even paying someone to help you ;)