Trying to be safe in a relationship makes you often keep your partner in a distance. The imaginary, or not, fear of being hurt, abused, exploited or exposed, makes you live part of your life and not the whole thing.
The question is why did you start this relationship, to be safe or to live and enjoy it? And are you ever really safe?
If you really want to have a worthy relationship, and I guess that's why you are reading this, you need to be fully open to your partner and this way make him/her open him/herself. On the other hand if this is impossible then you have to go away.
It doesn’t worth staying in a relationship that is based on fear, not even for the sake of the children. If you force your children to be part of a dysfunctional relationship/family they will experience this as a normal way of living; this means they will repeat the same patterns in their own relationships. This way you make more people unhappy.
Wanting to be safe is something that keeps you from living.
Of course I don’t recommend that you go on extreme sports or stupid dangerous actions just to prove that you are alive!
What I recommend is to live your life fully, allow experiences and emotions, and grow with them. Grow together with your partner and/or your friends.
Since we are talking about highly sensitive people (HSP), a meaningful relationship is very important for a sensitive person. Many sensitives try to be safe, but this usually means depression. So being safe is not being happy.
I understand that this defense is automatic and based on past experiences, but if you still want to live your life, ask for help to get rid of these automations.