Decaptare, this is totally normal to feel sad or like shit time to time in your life. This is the beauty of life and whatever you want it or not, sadness is coming... the most important question is how do you deal with your negative emotions??
You must learn how to cope with sadness or any negative emotions the right way.
Here are some things that really helped me(remeber the key is to occupy your mind with something useful, don't let your mind think about your sadness for too long or you will relapse)
1)Getting rid of your comfort zone:
when you feel sad, try to come out of your comfort zone. My examples of comming out of my comfort zone would be.... meeting new people, say a compliment to a girl, text a random girl or try to make someone smile epecially if you haven't seen this person smile in a while... etc (use your imagination whatever makes you come out of your comfort zone and this will occupy your mind)
2)Train your willpower :
Will power and self-discipline is like a muscle you have to exercise it to get good at it. Create daily tasks that you must accomplish, no matter what! start with easy tasks and work your way up.
3)Set your Hope on God:
No matter what but you can't set your hope on your friends or a girlfriend. Friends can betray you, girlfriend can leave you. Set your hope on something Who is above that.
4)Don't let your life to be ruin because of "pussy"
During your reboot, you will want to be emotionally connected to a girl more than ever! Watch out for that, don't be desperate. Take your time and be patient.
Hope that helps my friend and stay strong!