As far as I've known, if dissociation is usually present as a coping mechanism, than it will (if relied on heavily) produce a numbness of feeling, but numbness of feeling doesn't always mean that dissociation is present...there are some people who suffer from CPTSD and don't dissociate, but can feel numb just because they are emotionally overloaded, and their core beliefs took a proverbial sledgehammer to the face...PTSD rocks you to your core....making you feel 'numb' or in a sense detached from yourself because that which made you who you WERE feels like it exists no more...it leaves only the pieces of who you confidently USED to believe in, and even though you wake up, and try to resume a normal life for yourself, and those around you, you don't quite FEEL the same....your relationships with others you once knew may change as well...numbness of feeling can be treated with therapy, and trying to resume a life you once had. There will probably be days he'll be sad, numb, anxious, edgy, or depressed, and then there will be days where he'll be upbeat, loving life, positive, expressive, and joking...the numbness sets in and it passes in my experience.
I try not to dissociate so much, because in addition to numbness of emotions, there's memory problems that come about...I can't remember most of my life because of dissociation...birthdays, parties, childhood-to-adolescent rituals...all blank...there's also identity crisis, which I suffer from, which really is about experiencing a deep interpersonal conflict about who you are emotionally, mentally, physically, sexually...you feel like a stranger to yourself and no concept that you hold of yourself remains, it's like every day I begin life anew as another person with the same name, just different out look all together. you can't understand yourself, because most of the time you exist in an subconscious state that doesn't absorb the experience...so you never grow emotionally/personality-wise as a result, meaning you often don't cope with being around things that remind you of your abuse, or stress associated with your past.
I grew up with this, and it's effects are long-standing as a result; I don't know if your BF has any of these feelings, but here's a template of symptoms you can ask him about if he experiences. Best of Luck Heather to you and your BF! I'm sure he'll get through this with time, and support from you! Remember, he's STILL your BF, just trying to get HIMSELF back as much as you want him back. :)
