having trouble connecting to most steam multiplayer games

for some unknown reason; i cannot connect to most multiplayer games from steam; steam is saying they can't help me, and i'm starting to get fustrated; i'm using a ethernet connection; i ended up going hardwired recently, because i was having constant connection issues; my ping is also pretty bad; i thought it would have been better when i switched to a hard wired connection; i don't want to screw up my computer; i also switched to a gaming laptop recently; so that i could play more online games; when i play on minecraft online, i have constant connection issues; my online gaming buddies keep saying it's my internet; but it can't be my internet; i'm using a hard wired ethernet connection. i got a connection from my bedroom to my laptop; Telstra(my internet provider) has constantly said that there are no issues with my internet in my area. so i don't really know what the problem is; i could also port forward my internet so that i can play all games; but i don't want to screw up my internet connection

:)