Your post was NOT offensive, so please don't worry. The only thing I took issue with (and not in an angry or offended way) was the statement to the OP that she will always feel sad.
She may or she may not, as we both realize.
One thing I've found interesting in this journey is my poor track record in predicting how I would feel later. I won't belabor my point (I hope), but I originally didn't think I would do ART if we could conceive naturally. Then I thought I would never do DE if ivf with my own eggs failed. When I moved to DE, I never dreamed I could be as happy as I am now. And so on.
So I do think our feelings ebb & flow, evolve, etc. It's just impossible to know. It actually took me 4 DE cycles to finally get a BFP & years passed me by. I was bitter with the best of them during that time, but I don't feel any of that now. Others will forever retain some of it (bitterness, sadness, grief, whatever it is they feel).