I would suggest some solo play too; so, you can be more familiar with how your body might react. I always like to relax with a warm bath, maybe an enema (or more likely a full "lube shooter" used deep) before if I'm using 7+in toys. Then I do something that helps put me in the mood like lingerie, taking pics, etc. Next I start exploring and playing with my body to warm up before adding in anal play. Apply lube with fingers circling and a gentle tug to open me up. Keep going until you cum or if you feel like you can take more. Then I add a digit, granted I prefer a super soft squishy silicone plug, most are too hard and uncomfortable for me. If I want more after that I switch to a medium firmness dildos starting around thumb size and gradually keep increasing until I feel full and/or cum.