You are running onto one of a few issues, first you need to increase cals as you go, but there needs to be other changes, you eat the same and train the same gains and pumps slow quickly.
Using gear upregulates receptors so I don't really think it's possible to over satturate receptors, you are constantly making new ones. Your body strives for homeostasis, and it usually happens around that time, change your diet, add mote cals, different foods, change up your training a bit.
Also make sure you are running an Aromatase inhibitor (AI), hcg. Could possibly be myostatin. Its good to change compounds from time to time or add something new but it's your first cycle, so eat more trainer heavier and low reps, and you will continue to grow. Push yourself, gear only will do so much.