You really need to discuss your feelings with her. Tell her how ML with her makes you feel...the emotional connection. I literally had to explain to my H that there really is an emotional connection that I receive from the physical contact with him....without that physical contact I can feel part of that emotional connection drifting further and further away.
You've got to try to convey how all of this makes YOU feel on the inside. Yes, this will be difficult for you...it's definitely not going to be easy. But the road to recovery in a SSM is harder than hell, it takes a lot of hard work, it takes facing up to your own communication demons, it takes putting all of your emotional cards right out on the table for your SO...and it takes communicating what you need and what you aren't receiving.
It's not easy, it's very difficult...but at some point you simply have to screw up your courage and jump in I don't mean to sound callouse here...but there are going to be times she's offended by what you say...but you know what, as long as what you are saying is honest, not intentionally hurtful and truly speaks what you mean to say and are feeling...then you need to get these things out.
IMHO you cannot be worried about offending her by talking about sex, you cannot pussyfoot around the subject....that's what has gotten you here. Now of course that doesn't mean you bulldoze over here and start speaking crassly...but you start talking about this....and a good place to start is with how YOU are feeling without her.
I don't mean to sound callouse here...but there are going to be times she's offended by what you say...but you know what, as long as what you are saying is honest, not intentionally hurtful and truly speaks what you mean to say and are feeling...then you need to get these things out.