What does 惟覺 mean here? While lying in the hospital, I am thinking about 唐詩。 Particularly about this one:

   多情卻似總無情， 
　　惟覺樽前笑不成。 
　　蠟燭有心還惜別， 
　　替人垂淚到天明


I think I can more or less understand it, but I have no idea what 惟覺 means. My incomplete and ugly translation (only for showing I don't come here without trying) is:

Full of, affection, yet appearing unconcerned,
.... Laughter does not come out, in front of the wine cups
Candles, too, have a heart and grieve in parting,
They cry till dusk in people's stead.


Is there a word play with 燈芯?
I think  無情 is not "unconcerned", especially with the 總 there; more like "as if there had never been anything between us" (好像我們彼此從來沒有過半分戀情)

惟覺 = 只覺，但覺 etc.

It's a little bit like German doch, indicates an attitude, very hard to express in English. a little bit 無奈, perhaps? resigned sorrow; but put that in a translation and its spoiled.

"Now that we're sitting with wine glasses in front of us, I find that I can't even manage a smile."  Just a sentence, not poetry.

I agree that 心/芯 is the pun intended.  But since wick and heart are not homonyms in English, I'm stuck.  A truly tough poem to translate.