Do you ever feel guilty about feeling immensely happy while knowing there is incredible suffering happening?

No, never. Happiness is a gift - when I feel it, I rejoice in respect of that gift and try to p it on to someone else - to perpetuate happiness. Even at a funeral, I will try to highlight happiness for the good the deceased did while alive - to help support good memories, and not to try to support sadness by radiating sadness. If you want to get a good feeling, just turn someones tears into a smile of contentment by highlighting something good for them to enjoy the thought of. The part after "But then I realized" gave me pleasure in your realization and I thank you for that. Shine that light some more!