Lizzy is referring to Bingley and Darcy. The meeting had been stressful for her and Jane. Both sisters were awkward and concerned for the other. Darcy seemed to have reverted to silence and a distant attitude and their mother is being particularly embarrassing, sucking up to Bingley, babbling about Lydia's marriage and being barely civil to Darcy. Lizzy IMO feels worse than Jane, because she is the only one who knows how much the Bennet family owes Darcy. The pain felt by Lizzy on thinking about this visit outweighs the pleasure she felt at seeing both men again.