Home internet speeds

Hi Comcast support,
Internet speeds are extremely slow. I can’t connect to work meetings or vpn without meetings and calls getting dropped or disconnected. It’ has become extremely hard as this happens every time. I am on 75 mbps internet speed plan and I hardly get 10-15 mbps speed and it drops 2-3 mbps. I am a can’t keep count of how many time I had to get on the phone and reset modem and speak to customer care representatives.
I am paying 50$ for 75mbps plan and on most days I get 5-15 BMS speed and through the day it’s interruptions and speeds are less than 5 mbps..

Can someone help here and this is going on for months and have called the customer care for god knows how many times...