Might need to slowly start including some near max 2’s and submax 1’s. If you don’t like doing heavy 2’s or 1’s, you might try some near max board presses. You can probably triple your 1RM on a 3board press, and it gets you used to the heavier load without beating you up.
The first time I benched over 400, I had just seconds before completed a 3-board press with 475. The confidence it gave me to know that if I could just blast it up the first 4 inches, I had 75lbs. of reserve strength to finish the rep. Went up like a balloon.