How Can I Learn To Express My Feelings?

You're not able to express your feeling for one reason, Fear.  When you truly realize this you will be able to express yourself.

You practice using a gradient approach. Find someone really easy to express one emotion too. The lowest gradient would be doing this with a doll or pet. Then communicate with a friendly person and then another, etc.  You can express anger and then, fear, and then be antagonistic, and be bored, interest, strong interest, enthusiasm, up to action. You can work back down these emotions to grief, apathy, and work back up. Practice cycling through each one. Kids are great for cycling through these emotions naturally. You want to be at a high emotional level, and of course things in life will happen to reduce this, but you want to get back to a high. Don't get stuck in one emotion, especially a low one. I bet you have seen someone who is crying a lot or just apathetic. Some people are stuck in anger so get angry easy, or get afraid easy or bored.  Actors usually learn to cycle through these emotions.

Be honest with yourself first,then be honest with the people you wish to understand how you feel. People can only act on how you present yourself. TRUST ME an honest person will be understood and responded to generally in a positive light. Think before you speak,even an honest person must consider other people's feelings