Disconnecting every 5-15 seconds for 3-7 seconds since I changed my router.

So about a week ago , I changed my router because my old one is not working (currently in repair) , after that I started getting these constant disconnects every 5-15 seconds for 3-7 seconds. It's really annoying and I can't download something without pausing and resuming it again 10-30 times , or play online games like League of Legends.

My current router: Zoltrix ZW919
Previous: TP-LINK W something (dont remember)

If you need any info please do ask.