How can I comfort my partner who feels bad when I experience premature ejaculation?

Go again. Take a break to recover and spend a lot of time in foreplay with your partner until you get an erection and go again. No reason why you can't have multiple episodes in a session and everybody will be happy also you will note a tendency to last longer and longer with each episode.
Sex and rejection. Talk to your partner and assure your partner that it's nothing that the other person did wrong. Assure your partner that there is no inadequacy there. Listen to your partner's feelings, especially of disappointment, rejection, sadness, fear of losing you, and the like. Also, you might want to have a physical exam and consider counseling to find out if there are physical/ psychological reasons.