blossom end rot/rotten bottom tomato
Watering evenly and have dug some epsom salts into soil to help with calcium uptake. Is there anything I can rub on portions of tomato affected to inhibit rot from beginning?
Unfortunately, no. It sounds like you are doing what you can and this should hopefully be enough. You can also apply some mulch around the plants to help retain moisture. Many times it is not so much that the soil lacks calcium, but that the plant can't take it up in the right amounts. This article has some other suggestions on helping your plant be able to more efficiently take up the calcium: https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-blossom-rot.htm