Noni Madueke headed Arsenal in front on the hour mark, before Lewis-Potter scored a header of his own for the hosts 10 minutes later to settle the scoreline.
"Towards the end of the game, it could have gone either way, and on another day, we win it," said the winger.
"It was a bit crazy, to be honest!
"It was nail-biting towards the end, obviously you can't do too much sat on the bench, but at the same time I've got full belief in the boys as we've got an unbelievable squad."
On missing a chance a few minutes earlier by heading in the equaliser, he added: "You have to put it to the back of your mind and try and score the next one. Thankfully, I did that.
"I was disappointed I didn't score the first one and I tried to not let it eat away at me too much. When I got the second chance, I was not going to make the same mistake."