bottle up (phr v.)
Definition: To keep (a feeling or emotion) inside instead of expressing it; to hide (a feeling or emotion).
Please talk to me. Don't just bottle up your emotions like that.
Tension in the home increases if you bottle things up.
I know he's angry, but he bottles it up inside instead of talking to someone about it.
If you keep bottling up what you're thinking, we'll never be able to help you.