[AB] ping spikes while gaming

So recently we've switched from telus back to shaw and this time we got the High Speed 20 (speed tests have shown to be 20Mbps down and 0.5Mbs up so I'm just assuming, might have to check with my folks). This was a downgrade in terms of up speed by at least half (i.e, had 1Mbs Up before) and ever since then I've been having terrible ping spikes (from 80-90 to 600+ and then back down again in a endless loop) whenever my entire family decides to use the internet all at once. At first I thought it was just because they were all buffering videos all at once. However these 600+ ping spikes are hard to recreate as to isolate what websites are to blame for sucking up all the bandwidth. I do know that the initial buffer of youtube videos will cause a sudden spike from 80-90 to 100-200 but that settles back down to 80-90 when it has began loading. As I am typing this right now my sister is using the internet and I'm getting no pingspikes what so ever (I'm playing Team Fortress 2 and tracking my ping in there if that is anything to be considered; CSGO was the same as well). Earlier on however, when no one was using the internet my ping was spiking to 150 in about 2-3 sec intervals non stop. Obviously I've checked if I was downloading anything but of course there was nothing, just random ping spikes. Also my sister and I use the internet wired (but with the capability of connecting to wifi), where as our family laptop uses wifi only. Another strange thing that has happened since the ISP change was that I couldn't connect to the wifi on my computer any more. Before the change I could connect to the wifi network (I only had 1/5 bars, 2/5 at best) and be connected directly to the modem as well. Maybe it has something to do with the Shaw Go Wifi I'm not sure... I can provide more detailed information if necessary but I think the walls of text above is enough for now. Thanks in advance for the help