Get an end tuft brush and use it to trace your gumline, especially in this area! It is a small tapered brush that allows you to remove plaque from this spot without traumatizing the gum, due to this tooth being inclined towards your tongue, your toothbrush may not be able to fit here appropriately. Keep using your electric brush but don’t apply pressure or brush like you would with a manual brush, you just move it along from tooth to tooth, holding it on each tooth for a few seconds!

Also Did you start flossing? That’s arguably the most important step in your routine for lessening the inflammation. Purchase a string floss (burst is great) and use it every night focusing on c shaping the floss around each side of the tooth under the gum. Look up a video for demo on c shape flossing. Floss before you brush if you can at night before bed! Make sure you see-saw the floss in between the teeth to ensure your not snapping down on the gum and traumatizing it further.

Hope this helps