4 Months Post-op Rhinoplasty Nose Tip Still Bulbous, Could it Still be Swollen?

I suspect that there is still some swelling present, especially if it changes throughout the day, as you describe. A steroid injection might help regardless. Check with your surgeon.

The fact that your tip is larger in the morning proves that it is still swollen.   The tip of your nose is likely to shrink dramatically during the next several months as swelling further subsides.  My recommendation is against massaging and/or steroid injections at this time, but a double dose of patience will likely help.