Connection problems

Hey! So my problem is Im lagging very hard during the day and Im usually sleeping at night. I have a 4g/lte router in the window... We have no cable connection (I have to move for that... or being a billionare) so I have two options 4g (150+ mbit/s download) and microwave internet (around 5mbit/s download). Ofc inside the house Im using cat5 cable but thats not the problem. During the day 4g is not that good, like download speed can be around 16-80mbit/s. Even back in the old days if kind of everything was good with the microwave connection I had stabile 50-60ms. Why do I have insane lags? What can I do about it? I know its probably because a lot of people using the network and it burdens the network. How should I make it stable? Idk when it started probably half a year ago and Im using my 4g internet for years now. If im NOT using internet on any other device its still bad... stable 200 ping BETTER than when your ping is only go up for a second (I only know this because I played rainbow six on NA servers... actually I have better ping in r6 and it less laggy than valorant...)