Salamualikum sheikh can I say astaughfirullah and other dhikr but not keep count of it as it's hard? Will I still get the benefits of doing such dhikr? I was thinking of using a tally counter.

Ofcourse u get rewarded for making thikr, but if u mean the specific reward for a certain number then no. You dont need a counter. Do it on your fingers as they will speak for you on the day of judgement.