It sounds like you've already got it. When used by itself, the verb "sentir" means "to feel/sense". It can be used to express how you're feeling a tangible sensation (a stick in your hands, somebody touching you, etc), or to express what you're thinking.
- ¿Sientes esa brisa? Do you feel that breeze?
- Siento que está bien. I feel/think it's fine.
- Lo siento. I'm sorry. (I feel/regret it.)
When used reflexively (with the pronoun "me", in this case), the verb "sentir" takes on the meaning of "being in a state".
- I feel tired. Me siento cansado.