Will Changing My IP Help Stop Attacks on My Router?

I've been getting notifications from AT&T Smart Home Manager that they are blocking my Medialink wireless router from accessing several suspicious sites and even stopping a "Device Attack" on it. I've been dealing with hacking attempts on my accounts for the past two weeks, possibly due to leaked passwords. Since it seems someone might have accessed my router, I'm wondering if changing my IP could help deter these attacks. I've heard AT&T charges $30 a month for a static IP, but I thought I could change my dynamic IP on my own for free. Can anyone provide insight on this issue? Also, how worried should I be about malware on my router?