Help controlling Lag

[Halvium]

As you guys have known i've only just returned to ac but for some reason i'm getting extremely bad lag and pj spikes whenever I play on any server :/ my connection has never been as bad as it is now ac used to run so smoothly for me and these spikes have been gradually been getting worse to the point I can barely play anymore my tower isn't the best but it's faily decent and will run quite smoothly when it wants to here's how bad my lag is atm here's a demo + 2 screenshots for my ingame I play on a wired 100 Mbps British family connection (but I play when i'm the only one using the internet) which should be quite good for some servers in game but it's when I play them it turns ugly
Demo



any help you guys can offer would truly help me loads :)
my specs
4 CPU, 3.00 GHz, 448mb RAM, ADI Radeon Xpress 200