Internet has lots of dropped/slow packets

My COX internet has become extremely "glitchy" - lots of dropped packets and/or slow packets. What can I (or Cox) do to improve this? Please help - I bought a premium internet package, and it has become nearly unusable. I'm a software engineer that works from home, and I really depend on the internet working correctly for my livelyhood - thats why I signed up for one of your premium internet packages. It worked pretty well for the first month or so but keeps getting worse and worse. Please help!

Here is an example of what I'm talking about:

C:\Users\Bruce>ping google.com /n 10

Pinging google.com [216.58.219.46] with 32 bytes of data:
Request timed out.
Reply from 216.58.219.46: bytes=32 time=2909ms TTL=56
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Reply from 216.58.219.46: bytes=32 time=49ms TTL=56
Request timed out.

Ping statistics for 216.58.219.46:
    Packets: Sent = 10, Received = 2, Lost = 8 (80% loss),
Approximate round trip times in milli-seconds:
    Minimum = 49ms, Maximum = 2909ms, Average = 1479ms

C:\Users\Bruce>ping yahoo.com /n 10

Pinging yahoo.com [98.139.183.24] with 32 bytes of data:
Request timed out.
Reply from 98.139.183.24: bytes=32 time=2480ms TTL=53
Request timed out.
Reply from 98.139.183.24: bytes=32 time=2481ms TTL=53
Request timed out.
Request timed out.
Reply from 98.139.183.24: bytes=32 time=764ms TTL=53
Request timed out.
Request timed out.
Request timed out.

Ping statistics for 98.139.183.24:
    Packets: Sent = 10, Received = 3, Lost = 7 (70% loss),
Approximate round trip times in milli-seconds:
    Minimum = 764ms, Maximum = 2481ms, Average = 1908ms