Can't Orgasm

You have almost answered your own question. You have sited two things that you suspect are bothering you: being stressed from wedding preparations, and quitting your job so that you can care for your fiance's sons. These changes in and of themselves are stressful enough.

Stress causes the body to go into a state that is called sympathetic arousal. In this state, the body produces various chemical that are incompatible with sexual arousal. What's more, if you have negative feelings about the second change in your life (the taking care of his kids) then your body would be producing even more stress chemicals.

There's a bigger issue that I see operating here. In the last sentence of your letter, you ask, what can I do to improve. As if you aren't already doing enough! Now you're going to take on another task. It sounds to me like you are all to quick to carry more than your share of responsiblity. The problem is that people who are so helpful end up stressed out, pissed off, not to mention in a sexual stall. Your physical shut down is a warning. Your body is asking you to take stock in your life and see what is awry.

I suspect that what is wrong is your habit of taking on too many obligations, including those that should belong to others.

Read my Advice Archives to understand more about why you might be performing this role in life (low self-esteem, wanting to be liked). When you understand more about this pattern, then you can begin to work on it. When you meet this issue head on, and set better limits for yourself, you won't feel so stressed and dead from the neck down.