Upload Problems

Hi, So I've been having problems with my upload for awhile now. I have the Ultimate package which is 300 down 30 up, the problem is my upload is never consistent and this is a problem because I live stream. At first I never got anything above 2-3Mbps so I called cox and they sent a tech out and the tech said there was a lot of problems in the box on the street including a trap. He said he fixed the issues in the box and that if I was still having problems to call them back out to run a new line from the outside of my house to the inside as the line that runs through the walls was old, he also told me the modem I was renting from Cox was known to have problems. So after he left my uploads were about the same but I wasn't getting the packet loss that I was getting before. I called Cox and scheduled a tech to come out and replace the line i also starting doing research on modems and found out about the Puma 6 problems so i ordered the Netgear CM600 which has the Broadcom chipset.

Now here's where it's starts to get weird, after I set up the new modem and called Cox to activate it I ran some speed test and my results were awesome I was getting like 17-25Mbps on my upload, I was really happy and I thought the issue was fixed so I called up Cox to cancel the tech. About 2 hours later I noticed I was starting to drop frames so I ran some upload test and my upload speed was dropping lower and lower after each test until it back down to 3-6Mbps so I rescheduled the tech to come out but the following day when I woke up speeds were back up to 17-25 Mbps, then they dropped again. The tech came out replaced the lines and the speed went back up for about 5-6 hours but then they dropped again.

I don't know what the problem but my brain is about to explode. I need to fix w/e is causing this, I cant stream with upload that's all over the place and never consistent. If anyone has any ideas or suggestions I would really appreciate it.

I run all my speed test on Testmy.net and speedof.me and use the Twitch Bandwidth tool for connections quality. I'm also not wireless I'm hardwired.