I am so sorry you have had such bad luck with your past relationships.
And you are right when you say that you are scared to get any deeper than just chatting.
Have you thought of whether you have been subconsciously choosing the wrong guys in the first place? To answer this perhaps you would like to consider the relationship with your father.
This is the first love relationship we have and forms the basis of all our later relationships with other men.
I have chosen my husband subconsciously to resemble my father down to the last detail, his profession!!! Alas, however, he turned out to be different when he matured and mingled into the world big time!!!.
It also seems to me that chatting on the internet is also a subconscious effort to feel attractive and wanted without strings, because you do not really want to form another serious relationship.
What do you think?