Weired baby

My baby is not sleeping well since he was 3 weeks. First colic issue then 4 months sleep regression and now i dont know what has happened. He takes only 45 to 60 minutes nap. Total napping time is maxium 4 hours in 24 hours and other than that he sleeps 6.5 hours straight. Thats it. And that too he sleep in day time. At night only take naps.

He dont take feed well and is drooling , chewing. I think he is in teething. Iam feeling something on his gums. I it really TEETHING ?