Assuming you're correct, and not mis-reading the effects of VM's current over-utilisation problems (what does a BQM show?), then the simplest and most reliable way to change IP address is to buy your own wifi gear and put the hub in modem mode. But that gets you a one one-off change of IP address, the new one will be equally "sticky" and if you have been DOS'd then chances are you'll become a target again because something you're doing is annoying somebody else enough for them to want to DOS you. And since you probably have an established user name, even with a fresh IP address, they'll soon spot that "TiptonGamingWarriorGod" is back online (or whatever your user name is).
If you want to really sort out DOS problems, you need to subscribe to a gaming grade VPN, such as Nord VPN or Express VPN. A long term contract will be around £3-6 a month.
https://community.virginmedia.com/t5/Networking-and-WiFi/How-to-reset-my-IP/m-p/4614802
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