Being smothered is read as feeling crowded out by a relationship, a duty or an expectation that leaves you no air of your own. Being trapped in a small space with too little air points to circumstances closing in. Someone else being unable to breathe suggests worry that they are overwhelmed. Breaking free and breathing deeply is read as reclaiming space. The dream speaks of pressure and room to live, not of the lungs.
Where in your waking life have you met something like this lately?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.