I'm stuck in a loop

Trying to gain about 5 lbs. Need to increase my calories, The more active I get more calories I burn.

My BMR is 2250 Calories

Need to add 500 calories a Day to gain 5 lbs in couple months,

So after trying to increase my Calories to 2600-2700, I lost 2 lbs. My energy and activity level has increased so burning more calories. So I have to increase my calorie intake buy more than I burn. Hard to monitor and keep track.

A 10 mile bike ride I'm burning off any extra calories.
The more activity I do the more I need. As my energy level increases I burn off any extra.

Since I do not eat just empty starchy carbs, and sugar packing on extra calories is difficult. Nutrient and Calorie dense foods, fill you up much more & longer and I don't As Hungry.