Hi mikeyjon.
Tbh it does sound like you may have OCD - to my mind, the way you have to do things more than once, as you are not convinced that you have done them right, sounds familiar, as does the way you are convinced that something horrible might happen which will all be your fault if you have made a mistake. Though of course, the only person that can make a diagnosis is a ?GP/psychologist/psychiatrist/. Question is of course, even if you do have a mild degree of OCD, does the checking etc bother you?
Personally I have found counsellors as much use as chocolate teapots for OCD! Yes, it's happening because you are stressed/have low self-esteem etc - but I think you need to get at stopping the specific behaviours, such as checking, first, before going down the counselling route of looking at your childhood etc. If it is OCD, the treatment for this is ADs and/or CBT - cognitive behaviour therapy. IMHO CBT is better in the long term.
The good news, as it were, is that if you have mild OCD then there is a lot you can do to try and help yourself - sometimes just reading about, realising that you're not the only one out there doing these things, and that there is a reason for them can be very helpful for startes. There are also some very good self-help books you can get as well on Amazon, and some good web sites that give advice about CBT techniques for stopping the compulsive checking.
There is the no panic web site:-
nopanic
and the obsessive compulsive foundation website:-
ocf
The OCF website also contains some OCD screening questionnaires
Good books are:
Lee Baer - Getting Control
Hyman & Pedrick - OCD Work Book
Ian Osborn - Tormenting thoughts and secret rituals