A weak positive on the tTG test is still positive. If you had a weak positive on a pregnancy test, would you doubt whether you were pregnant or not? You either are or aren't, same with celiac.
positive is positive and negative is negative. there are no inbetweens.
it is not unusual to be overwhelmed by the voluminous, and sometimes confliciting, information available (not to mention all the scams, hoaxes and greedy sob's out there). mostly, no matter how smart you are, evaluating all the information is a matter of 'context'. and most folks do not have the experience and/or training to evaluate/synthesize all the information.
it is one of the huge values of this board -- lots of folks with years of experience dealing with what are,, sometimes, very individualized problems.
it is certainly a daunting task when starting, but does, as noted before, get easier.