It sounds to me like you have put in a lot of effort into your marriage, and have come to realise that sometimes things are not meant to be, whether in time this may change depends. But you both seem like you have come to a very hard realisation that is best for the both of you, that does not mean that you are not upset or devastated it just means that your a wiser and better person for leaving a situation that is not right for both of you, and leaving it with the love and respect you feel towards each other still in tact, which may in time lead to a great friendship or a reconciliation. But i think you both feel like this is the right thing, so hang in there because you still have to grieve and have a rocky road ahead of you, but hold on to the belief that this is for the best as you put it.