I don't want my husband's best friend over every week
Why don't you want your husband's friend over every week?
Because he's here too often and my husband doesn't have enough time to spend with me.
That is understandable. It can be frustrating to feel that way. Tell your husband how you feel.
Shit. I blame this situation on my husband and his friend.
You need to tell him that you want to spend more alone time with him. He should understand the situation and be willing to do so.