This problem appears to be adjustment issue with most likely dysthymia. The fisrt thing require is to improve interpersonal relation with spouse not becouse you are wrong but in order to solve your problem. Reason for loneliness is obvious that should improve first followed by resolution of other issue. Contact qualified psychologist to resolve your issues.

Through experience I have observed that many a times ladies ignore themselves and prioritise there family over self. I am not saying this is completely wrong but I am trying to say is that you also need some time for yourself some 'me' time say minimum half n hour per day where you do what you feel like, this will keep you happy. In addition to this marital counselling sessions will also benefit you. If need be Psychologist will refer you to a Psychiatrist.

You could have experienced a post partum depression during that time. May be you didn’t know how to handle  that at that time. Because of those incidents,  you both would have lost interest in each other,  which made you to distance yourself. The loneliness  is also because,  you do not feel wanted.