Perhaps you could convey your concerns without the jargon. I've found, through therapy, that just saying how I feel and what I need simply works best. I don't tell my husband I have attachment issues stemming from early trauma: I tell him it really helps me to have my therapist to turn to and rely on to help me be a better mom since mine isn't trustworthy. That's just sort of a generic example, but I think the key is figuring out what you want from him, not just telling to tell.

I tend to tell my husband about things that are emotionally stressful to help defuse them and sometimes to get some encouragement and support, or to clarify a relationship concern. I stick mostly with talking about concrete events: "I was talking about XYZ in therapy and it was hard because ____________." And then he'll respond or I'll explain a bit about what I need, whether it's understanding or a hug or just to vent, or often, to get his opinion as a more objective party.

It is a legitimate worry that you'll grow apart. I hope you'll be really honest and plain with him about your needs, especially during this difficult time having lost your mother. I figure that's being fair: if we are honest and ask for what we need and try to meet the other person's needs as well, we can take this journey in good conscience. I'm very fortunate my husband has stepped up and joined me on the path. He's gotten into therapy at my request, and made other significant changes, so it is definitely possible to stay close, though it can be a bit of a bumpy and scary road.