Help With Internet Lag

So after having comcast for a few months now the speeds have been great and have had no issues with internet connectivity. a few days ago my internet was shut off due to non-payment. the same day i paid the needed amount to restore the service and ever since i have been seeing horrible lag, i have checked my speeds to my box and its coming upwards of 235mbps. but i am only now recieving around 20mbps if im lucky to my computer.  ive tried trouble shootting everything and im still with serious lag, any thoughts?