Initiation

I’m a very shy girl, I’ve been with my SO for almost 2 years and I’ve never been more comfortable with a person but I’m still very shy with initiating sex, there’s some part of my brain hat won’t let me, he knows this and he completely understands but he still sometimes talks about how he wishes I would initiate, and I agree, I would like to but being so shy about and not really having initiated before I don’t really know what to do.