Although I understand how emotional this whole dieting thing can be, I don't think it is worth aiming for a set weight loss each week when you are ssing.
The reason being is that we know that if you do the diet in the recommended way then your body will lose the maximum safest amount it can each week and there isn't a lot you can do except stick with it and tick the days off.
By aiming for a set amount each week you set yourself up for disappointment on something you have no control over above actually sticking to the diet in the first place.
If you aim to lose 4lbs a week and 'only' lose 3 then how's that going to make you feel when you fail to meet your goal in full? If you consistently lose 5 lbs then you run the risk of upping your aim to 5lbs and at some point you are going to come unstuck.
I tried to have the attitude that I trust the diet and all I would do was to hang on in there whilst doing all the right things. I didn't try to quantify my aims any more than this because I didn't see the point of quantifying something when I was already doing the best I could