Oh sweetie, calm yourself down. You have nothing to feel guilty about at all. What your dog did for you is something lovely and natural and I'm quite sure she enjoyed doing it for you as much as you enjoyed her giving it to you. Don't worry about her not wanting you to give her oral right away, just take your time and be loving with her. Crawl up in the bed with her and cuddle, gently rub her belly and tell her how much you love her, she will understand. Just go slow, you don't have to give her oral right away, work up to it. After receiving much good advice here on this forum, that's exactly what I did with my Rottweiler Sadie. We were already cuddling together, I loved the way she would crawl on top of my naked body and rub herself all over me. It took some time before I was able to coax her into allowing me to give her oral but oh how she loved it when I finally did.
Do your homework and find her clit because it's in a totally different place than on a woman. I even found a unique pin sized vibrator at a swap meet in Northwest Florida that I use on her that drives her wild. Just remember Rome wasn't built in a day as is the case with building a loving sexual relationship with your pet and I'm sure everything will work out just fine between the two of you.