Welcome to our forum.
"Does anyone have any advice on how to take the steps into transitioning to a clean slate for the three of us since this is a new relationship for all three?"
Alas, I know of no way to clean the slate (shy of a lobotomy). The relationship was started and no matter how messy it was in the beginning, that part will remain in your memory, and you will have to process it.
I just know that many relationships get easier a little at a time, as time goes on. You have to get better at communicating with each other, find peace (and a healthy level of independence) within yourselves as individuals, and learn by trial and error what tips and tricks work with each other.
Hopefully your boyfriend will be more honest from now on. Also, try not to rush anything. Take time to appreciate all that you have with each other in the here and now.
Keep reading and posting any thoughts or questions you may have.
Glad to have you aboard,