[AB] Latency Spikes in Games (Int. 15, Hitron CGNM-2250)

Hi guys, I've been having consistent latency issues within my games such as CS:GO and League of Legends. My ping would gradually increase from around 40ms to 900ms over a span of 5-10 seconds, and then it slowly reverts back to 40ms - which then cycles continuously while I game. I've experienced this latency issue ever since I've made the switch from Telus. Generally, there are around 2 other computer with low-bandwidth users (browsing and e-mails), so I don't believe the 512 kbps upload is bottle-necking and causing buffer bloat. I'm just wondering if anyone else on this forum is going through this as well, or if anyone has a solution out there! Internet 15 - 15 Mbps/512 kbps Router/Modem - Hitron CGNM-2250