In time, you will get better. Give yourself time. You will learn which people to let in and which to keep out. It is a learning process. You will also develop more of your sense of self which will help you to determine which feelings are yours and which don't belong to you. You will also learn to set boundaries (be assertive).
Just take it a day at a time and don't be hard on yourself. You will grow and strengthen so that you will be able to take on the world better. Right now, you're just really sensitive and that's okay. You've discovered this about yourself and that's just the beginning. Now you will begin to learn your place in the world and how to use your gifts. But again, it takes time and life experience. Just be patient