What are you smoking that it looks like Nasus's gets 200 HP per q stack before having TF with SV?! Early game his passive barely gives 20-70 HP and that depends on amount of stacks.
Most meta top laners can do so much damage to Nasus early that every stack he goes for he risks an all in and losing 50% if not all his health. This is especially true against conqueror abusers with ignite.
His slow is a single target ability that is his only means of engagement or disengagement... 1v1 he is strong if allowed to get ahead but the second he is focused and CC'd he dies extremely fast.
This is a QQ post that just tells everyone you don't know how to play against Nasus and that nothing is wrong with the championship but your own play style.