the loss of the passion, the gung ho... is to be expected with all that has happened in your life.
Men do not like to think about or admit that they are affected by their emotions, but we in fact are...sometimes healing/feeling normal after a loss takes some time... get on the bike and get going...let it help you heal...putting the weight back on was part of the grieving, let riding be part of the healing... good luck and keep it fun.