You seem to have two routers, which is undesirable, but not the problem here. You already have a ping spike to the first hop outside of your own network (3), so I'm guessing you're suffering from bufferbloat due to a congested connection.

The DSLReports speedtest (http://www.dslreports.com/speedtest) will tell you how much (looks like it will be at least 300ms).

There are two possible solutions:
1. Replace your two routers with 1 good one that can do SQM-QoS. This way you'll never have to worry about what others (or your own PC) decides to do while gaming.
2. Stop whatever is causing your connection to get congested. This might lead to fun discussions with family members or house mates to make them stop downloading, youtubing, netflix when you game.

Run a WinMRT to a known good server (e.g. 8.8.8.8) and make a screenshot of the results after you've experience a ping spike.

He's trade banned on Steam now, since his Steam transactions also got charged back.

Pretty much this. There was also a significant server CPU increase, causing half of my server capacity to struggle with 9v9 at 133Hz.

I don't think they accept reports about non-item transactions. Also, the person now claims to have used "mom's card" without approval. Causing all his purchases to be charged back now (my transaction was from Feb 16 :/ )
If true (which I doubt) it's kind of amazing you can scam businesses out of their money months later because you let your dumb kid use your card.

Got scammed out of 140 euros after a creditcard chargeback by this person:
http://steamcommunity.com/profiles/76561198268931774

Had to reduce the amount of available free servers as a result and I've disabled the expensive premium options indefinitely.

• Got 10 more DDoS protected servers in EU (OrageBrigade)
  
• Marked the DDoS protected servers in the list with (Anti-DDoS). 18 total for now.
  
• Ended the 3 servers in the 133Hz experiment, reverted back to stock

I'd rather downfrag my own site than upvote a nutshiny post.

serveme.tf is free to try, so you could always give it a go. Unfortunately only the BeretBrigade servers have DDoS protection that really works. That machine is hosted in France though, so might not be good for you in Latvia.

NFOservers has decent DDoS protection in the US, I don't know if their EU servers have the same protection, but the NA stuff is good enough for most attacks. They filter the attacks upstream so they stop hitting your server.

Hiperz is still good in my opinion, I really like the ability to rehost your server to a different region/location if you have bad routing for example (this does cost extra).

A dedicated machine from OVH in their GAME range comes with a proper anti-DDoS solution that's tailored for game servers. You're talking 40+ euros/month though, so you might want to look for someone to split the bill with.

It's not so funny if you're the one paying for the servers.

The best player in the world, who made the best team in the world, on his way to win the biggest prizepool TF2 has ever seen, should have wished his opponents a speedy recovery. You know, sportsmanship, or being a normal human with empathy.

I'd just like to say the stream looks great. Very smooth 60FPS, great encoding quality and good observing, thank you <3

http://fakkelbrigade.eu/i/vanillamarvin_varwwwvanilla_2018-01-29_12-44-25.png

???

https://blog.gravatar.com/2010/04/01/unicorn-gravatars-stack-overflow/

Crap, missed that. Can you record your own vid with net_graph 5?

Check if your router has flood or DoS protection. If it does, disable it.

Your WinMTR shows two routers (192.168.1.1 and 192.168.0.1). Not likely to be the cause here, but undesirable. There's at least 1 ping spike to the 192.168.0.1 router, which is odd if it's on the local network.

I've not seen you mention reinstalling TF2 (and starting completely stock first, no fancy configs) and reinstalling Windows, try those, in that order.

I see you've tried using your PC somewhere else and getting the same problem, but still, can you describe your network setup? Is it a true ethernet connection or something like a powerline adapter? Because those are almost as unreliable as wifi for gaming. What router(s) are you using? How are you connected to these routers exactly?
What kind of network adapter do you use in your PC?

Judging from your video, something happens causing you to receive less packets (see "in" packets/sec drop below 66 when it lags), but at the same time you appear to receive more data (see the "in" k/sec). This is counter-intuitive, but could make sense if these packets arrive out of order or are somehow corrupted / unusable.