I use to fumble when I speak. I am used to the remarks that people pass when I am stuck in a sentence. All that worry me is the interesting fact that when I speak to my friends or outsiders (other than my family members) I speak like normal people (or get slightest of fumbles that are negligible) but when I speak to my family, this disability shoots up and I get stuck on 80% of the words in a sentence. Although my family donot complain about it but I am worried. Moreover, this disability goes up and down in some uncertain periods.

I am sure that this ability is linked to some factor other than tongue, as it does not happen all the time. I want to get rid of this, Is there anyone who can help me?