You are on the journey to a successful relationship and hopefully, marriage. Your reluctance to speak spontaneously is something that most folks share. It seems that we have a problem with a fear about sounding demanding or overbearing. It is all in the way that you shape and phrase your conversation. The trick here is to practise in advance and when you are happy with the way it sounds, tell him how it is for you.The thing to remember is that men are not mindreaders and nor should they have to be. Most males appreciate hearing it "like it is".The problem arises because most females are raised to not "tell it like it is". They talk around the issue rather that get to the core of the issue.Straight talking will win eveytime. You say that you resort to passive measures to solve problems.That style usually employs a large slice of manipulation - big problem.
I would encourage you to persist in exploring the work that you know you need to do. You are intelligent and self aware and these qualities will assist you greatly in your relationship issues.
Practice taking the initiative. I know that it does not come naturally, but it is a valuable habit to acquire.
As far as your nervousness goes,remember this -we are always nervous when we are approaching a new venture which contains some RISK. It is natural and it helps us become alert if the apprehension is at a low level.However if you are really SCARED, talk to your guy for as long as it takes to experience a reduction in yout anxiety -talking works, but follow thru action is even more powerful.. Good luck.... Jac