blocking your partner emotionally

I am still not sure how I ended up in this train of thoughts, because originally I had thought about the way we connect and feel more intimacy. Well, this was the first plan, because of my fantastic, mind-blowing experience during the weekend, yes, the one with the new cane.
Instead, after some dreaming and reminiscing about it, my thoughts went into a rather dreary direction. No depression, PMS still kept in check, just some thoughts that created horrible pictures in my head. I never had any trouble of this kind with Master, but I found the pictures they created in me horrible; what, if you actively or unintentionally blocked your partner out of your feelings? Would not let him participate emotionally? The physical aspects are pretty obvious, I guess. If you don't want to let go at all, he would have a hard time of succeeding with anything. And, yes, sex again, if you are all unwilling to relax, sex is probably going to hurt. Nasty pain, not pleasure, and definitely not the kind that ends up in heaven and bliss, I won't linger on these details though, because they are definitely too disturbing for me, they are the stuff my nightmares come from, if I have any. I'd rather go and watch a Zombie-movie than go into the depths of such depressing thoughts, even though I am the one who is afraid of those movies.
Nevertheless, it can still happen, even without you noticing about it, that you don't let go, that you do not let him participate in your emotional state. If that happens unintentionally, ok, I think in a relationship which is really about being close and being connected, sooner or later, you are going to talk and solve the problem, at least if you see that the problem is there.
In our relationship I am happy to say that we don't have much of that problem, at least not to such a horrible degree, and definitely not like an active blockade. That would be a real disaster, because it would mean that you play around with your relationship, and do not care much  for the well-being of your partner, though taking care, loving and trusting are vital parts of any relationship.
If one of the two of us is in such a state, like shutting him-/herself away from the other one, it is because of other problems, which are not even connected to the partner. I think that it is pretty normal that sooner or later you take some kind of trouble home and it might just happen that this absorbs more of your energy and thoughts than it should. Usually it is me again, you could have guessed, who ends up in that kind of problem, where even minor problems appear like major ones and they create sorrow in me, where Master would just shrug that off and say 'who cares'. I am not good at that at all, and even Master has such moments, where some business-affairs absorb not only his time but also his attention when it is not necessary and he should relax.
From my experience, it is far easier to see the problems your partner might have, than your own. Master tells me, when I start being like a fortress, which is good, because I do not realise such things  about myself quickly. Instead, I can see that something might bother him, that his thoughts are away, or that he is emotionally detached for a time. I hate that completely, and I am allowed to talk to him about such things, almost any time, any place, which I am extremely grateful for. What I mean here is not that I am all needy for his attention .....hm, ok, yes probably that too, but any sign of being emotionally away from my partner feels for me like being close to the abyss, a black one, without a cushion at the bottom to soften your fall. Pure horror.