I am incapable of putting how I feel into one question, my struggle is I don’t know

Hello, first I want you to know that it is impressive how you were able to gain insight after you wrote your question. I have to say I believe that you know yourself well enough to acknowledge what might be going on. Recite these words,"I am brave because I was able to confront the way I am feeling." The first step in healing is accepting that the way you have been doing things can be improved. Your message appears to describe difficulty with communication and expressing your feelings and thoughts. Emotional maturity comes from nurturing, actual age, and practice. Were your feelings nurtured as a child? Lots of times when we feel unheard and misunderstood we get defensive aka: "switch off, wall up" just as you mentioned. Your feeling of being hurt is valid if you are feeling unheard. What I would suggest is using "I" statements to communicate with others. Here is an example I feel _______ because ___________.  Really think about how you feel and why you are feeling that way. It is best to avoid using the word you to start to express your emotions. When the person you are speaking to hears the word You, they will get defensive and might say hurtful things. Those hurtful things they say may validate some of the negative beliefs you are already experiencing. Does that make sense? When this happens this is a vicious cycle of poor communication until someone shuts down. 

Next, and probably most importantly is going to be for you to practice self kindness. I know, easier said than done. Try your best to acknowledge when a negative thinking pattern starts. Now when you do recognize that you are being mean to yourself replace that with something kind about yourself. Possibly stating what one of your strengths are. Again, this takes lots of practice. Lastly you mentioned not loving yourself. Lack of self love can make it extremely difficult to believe in yourself or practice kind self talk. As you state you are in search of validation. Start with self validation. Find those things that are positive and true and begin to claim them. Acknowledge self criticism and then change the language you are using about yourself. A way to practice this is to think of someone saying these things about your best friend or her/him saying these things about him/her self. Would you agree with that person? Probably not and you might find the words to contradict what is being said. Try that for yourself. 

I will teach you a practice to enhance self love. In the morning when you wake up go to your mirror. Place your hand over your heart and say Goodmorning (state your name), I love you. Do this daily until you start to feel the love for yourself. You'll know when, the way you felt when the person who you know loved you most in the world told or tells you they love you! I hope this was helpful. Be well, be kind, and emit positivity into the world so it can come back you! Good luck!