Hi there happypossible;
It's wise of you to think through the pros and cons of parenting plans and custody arrangements. Good to hear you have a therapist you can talk to about all of this, too. Do you have a lawyer right now, as well?
One common misunderstanding that some people have is that "sole custody" has to do with how much time children spend with each parent. "If I have sole custody, then the kids will never see the other parent". That is not the case (though the terminology can vary state by state).
Custody generally has to do with legal decision making. In the past, it sometimes got confused with
parenting time, which is the schedule for when the child is with each parent. You may hear outdated references like "whose custody weekend is it" and that is not necessarily accurate. That being said, there are still some states that differentiate between legal custody and physical custody, but physical custody generally means parenting time.
In our state, there is just "sole custody" and "joint custody", and those refer to legal decision making only. There is no relationship between a parent having sole custody, and that parent then also having more parenting time.
It is totally possible (in our state, for example) for one parent to have "sole custody" (tiebreaker on all legal decisions such as medical, dental, mental health, school, etc) and for both parents to have equal parenting time. It's also theoretically possible (though uncommon) for one parent to have "sole custody" and the other parent to have majority parenting time.
When your T suggests that you should pursue sole custody, is your T suggesting that you pursue sole
legal custody? Or majority
parenting time? Or both? (or something else?)
Generally speaking, you could have sole custody, but then try to work together with your ex to come up with a parenting plan that is as balanced as the two of you can agree on. (Not saying I would recommend that in your case, necessarily). The point is -- having sole legal custody has no relationship to "taking the child away from the other parent".
I wonder if getting some clarity on your T's suggestion could be helpful in coming up with a plan that's best for your child?
And I'm also curious if you have talked with your T about this feeling:
I’m not trying to keep her from him.
Is that guilt, or something else?
...
Anyway, there's a lot going on for you, and it's good that you're wanting to put your kid's well-being first.