I feel so empty inside. Like no emotions at all.
I'm sad for you, but why do you feel empty, may I ask?
I don't know. I just can't seem to feel anything.
I'm sure everyone feels like that sometime in their life but it's not a good thing. You should probably seek help or try to talk it out with someone. Feeling emotions also allows you to feel empathy for others which is a crucial thing to have in life.
I just want to feel happy.
I know and I am glad that you seem to know what is the problem with you and the next step is finding out how you can resolve it, by again, talking with someone about it. It would only get better from here and I hope you find happiness again.