c6300 flood attacks, slow internet and eventually losing internet multiple times daily

I have a c6300 router that was purchased about 6 months ago (via amazon and still new in box) to replace the exact same model for easier set up on my end. I have multiple devices connected (2 phones, ipads, wifi cams, multiple laptops and firetv). Performance has been excellent wired and wirless the past few years, but after cancelling my cable package and going with internet only via comcast last week I have had numerous spontaneous router restarts and intermittent loss of connectivity DAILY. Comcast ran their tools and says everything looks fine on their end, and their only suggestion is to reboot router or get a new one.

I checked the logs and am seeing DOS/ICMP flood attacks that appear to correspond with the connectivity issues and router restarts. A few of the IPs below appear to correspond to Amazon and I have been streaming tv/movies from Amazon fire using HULU, Netflix and PlutoTV. But honestly Im not that experienced with advanced networking or DOS/ICMP flood attacks and do not even know what is relevant below. Any help on what settings I can update or steps I can take to track down and fix the connectivity issues? My wife is working from home and losing internet multiple times a day is killing us.

[DoS attack] ICMP Flood from fe80:0000:0000:0000:1a8b:9dff:fed3:bc22 1 Monday, 10 Jun 2019 10:25:45 ff02:0000:0000:0000:0000:0000:0000:0001 fe80:0000:0000:0000:1a8b:9dff:fed3:bc22 [DoS attack] ICMP Flood from 52.53.208.247 1 Monday, 10 Jun 2019 10:22:05 XXXXXXXXXXXX 52.53.208.247 [DoS attack] ICMP Flood from 54.95.189.179 1 Monday, 10 Jun 2019 10:21:24 XXXXXXXXX 54.95.189.179 [DoS attack] ICMP Flood from fe80:0000:0000:0000:1a8b:9dff:fed3:bc22 1 Monday, 10 Jun 2019 10:15:20 ff02:0000:0000:0000:0000:0000:0000:0001 fe80:0000:0000:0000:1a8b:9dff:fed3:bc22 [DoS attack] ICMP Flood from 54.245.58.230 1 Monday, 10 Jun 2019 10:12:33 XXXXXXXXXX 54.245.58.230 [DHCP IP: (192.168.0.35)] to MAC address 70:14:a6:43:4f:fc 1 Monday, 10 Jun 2019 10:11:32 0.0.0.0 0.0.0.0 [DoS attack] ICMP Flood from 35.178.203.218 1 Monday, 10 Jun 2019 10:10:59 XXXXXXXXXXXXX 35.178.203.218 [DHCP IP: (192.168.0.22)] to MAC address 0e:80:62:d0:06:34 1 Monday, 10 Jun 2019 10:10:11 0.0.0.0 0.0.0.0 [DHCP IP: (192.168.0.28)] to MAC address 9c:e6:5e:61:91:5f 1 Monday, 10 Jun 2019 10:09:53 0.0.0.0 0.0.0.0 [DHCP IP: (192.168.0.34)] to MAC address 14:10:9f:8a:d8:0a 1 Monday, 10 Jun 2019 10:09:46 0.0.0.0 0.0.0.0 [DHCP IP: (192.168.0.40)] to MAC address 78:31:c1:d6:02:aa 1 Monday, 10 Jun 2019 10:09:40 0.0.0.0 0.0.0.0 [DHCP IP: (192.168.0.21)] to MAC address 48:e2:44:88:ac:b3 1 Monday, 10 Jun 2019 10:09:37 0.0.0.0 0.0.0.0 [DoS attack] ICMP Flood from fe80:0000:0000:0000:1a8b:9dff:fed3:bc22 1 Monday, 10 Jun 2019 10:04:54 ff02:0000:0000:0000:0000:0000:0000:0001 fe80:0000:0000:0000:1a8b:9dff:fed3:bc22 [admin login] from source 192.168.0.55 1 Monday, 10 Jun 2019 10:04:23 0.0.0.0 192.168.0.87 [DoS attack] ICMP Flood from fe80:0000:0000:0000:1a8b:9dff:fed3:bc22 1 Monday, 10 Jun 2019 09:54:28 ff02:0000:0000:0000:0000:0000:0000:0001 fe80:0000:0000:0000:1a8b:9dff:fed3:bc22