Surface pro 8 veryr very slow

I purchased Surface pro 8 around 9 months back... and was excited about it... but for last 4 months it has suddenly gone very very slow like 1/10 of speed... i have tried everything but not able to make it work back.... even switching it on also makes a broken sound.....if i log in into other laptops it is working fine... please help or else i shall never buy any Microsoft products...