In Spanish, you need to use the word "estar" to express your feelings.

Here are some common feeling words that people use:

happy = feliz

sad = triste

shy = tímido/a

surprise = sorpresa

angry = enojado/a

anxious = ansioso/a

furious = furioso/a

nervous = nervioso/a

sick = enfermo

For more words, click on this link: http://medicalspanish.com/basic-vocabulary/feelings.html

This image shows how to conjugate the verb, "estar". (presente = present)

For example, I feel/am sad.

= Yo estoy triste.

She feels sad.

= Ella está triste.

I feel/am happy.

= Yo estoy feliz.

He feels happy.

= Él está feliz.

Never use "ser" to express your feelings in Spanish.

Yo soy triste(x).

Yo soy feliz(x).