I apologize for the length of this post, in advance - seems this always happens when I start thinking about my own experiences! LOL
When I left my ex, we had two sons that we needed to communicate together about. Of course, any communications with my ex was an exercise in futility and he never, ever placed the well-beings of our sons, first, before his ego. I would even find myself feeding into his supply by stroking his ego (rather than discussing why our eldest son had run away from home), or by attempting to chit-chat about HIS interests (rather than demanding that he take an active role, even though we were divorcing). He had effectively severed all of my ties with my safety network and frienships, so I was pretty much alone without friends to help me through. Because he had chosen our "mutual" friends, I had little hope of finding support from them - he had already told them that I had left him for another man, but that I had "turned lesbo" at the same time.
As a matter of fact, one of the things that I did was to keep a running log of all conversations that we had. I would also copy and file away (paper copies, not computer memory) any correspondences that went between us. About 2 months ago, I had to go through those piles and piles of papers and became physically ill when I started reading through the %¤#&!§-that I played into after I left that man.
We ALL go through that WITHOLD/REWARD game when we're dealing with a narcissist - whether it's a boyfiend (not a typo), parent, sibling, coworker, etc. They will reward us with their attention when we give them their narcissistic supply. And, we have to learn the hard way - we wouldn't have chosen these %¤#&!§-s if we had known what we were in for, right? So, we have to learn in the most painful way. The upside of this is that the difficult, hard, painful road to awareness has its own benefits: we can evolve into wise Survivors by experience. Some folks (ME, especially) can be beaten over the head with the Shoe Of Knowledge and I just don't get Today's Lesson unless I pick up the shoe and put my nose in it, personally.
Bottom line here, Trysten, is that we all make mistakes. Sometimes a number of times before we get the gist of the Lesson. Once you've acknowledged that Love does not require Pain, you'll be able to move on and begin to focus on evolving your Self (Life's Spark) beyond this particular point in your Life's Road. Although I understand your heartbreak only too well from my own personal experiences, this is only a temporary situation. This will not go on for the rest of your life, I promise.
About the mutual friends issue, do not discuss the issues between the two of you with ANYbody who is a "mutual" friend or even people that you believe are "best" friends - the narcissist is very careful to cover all bases where their property is concerned and they invent the most ludicrous stories possible in order to make us, the victims of their games, look as if we're just nuts. Well-meaning friends will often be coerced into "reporting" what we've been discussing with them and twist any tidbit of our personal lives around to use as weapons against us. Mutual friends with a narcissist are usually those people that the narcissist has screened and approved for his supply. They do not realize that they are being used and invariably get deeply involved in the deceptions that the narcissist will concoct to make themselves look better. "What happened to you guys?" can gently be answered with, "We just didn't have the same interests." Nothing more needs to be said. No defenses need to be invented to justify your actions. Nobody is deserving of an explanation - you are allowed (ENCOURAGED) to make wise decisions that will have a positive long-term effect on your Self. Anybody who wants to continue to discuss this guy needs to be cut off at the knees with, "I don't wish to discuss him, but thanks for your concern." End it right there - not one word more. This will put the ball back into their court and force them to either mind their own business or, if they're really dense, pursue the issue. At that point, you are thoroughly allowed to respond by saying, "These issues really are none of your business unless I invite you to discuss them with me - I haven't, so let's move on to a positive topic."
You'll come out of this just fine, Trysten. Right now, it seems like the universe is just caving in on you, but that's what the narcissist is expecting from us and that's how they play their abusive games by making US feel as if WE are the ones who have deliberately inflicted damage for our own entertainment! You will be just fine and you'll be wiser for your experience.
Best of wishes to you!