So sorry for your lose.
It is very hard to deal with the reality that your best friend and mentor, is not at your fingertips.(the phone)
I still have my Dad’s phone number in my phone and he has been gone it will be 8 years in August. Instead of phoning, I just talk out loud to him when I’m alone. Especially when I’m troubled with decision making, or it’s a holiday that we would have enjoyed together.
Won’t lie to you, the pain never goes away....it lessens and you will adjust because he is with you in everything you do and say.
God Bless you and your family during this time.