Sudden FPS Drops - Same PC i've had working fine for 1 year

Ristris

Prominent
May 17, 2017
2
0
510
Hey guys,i come here to explain the whole situation is starting to happen at me,
I got this pc:
Intel Core I3 2120
GTX 950
8gb ram(2x4)
Normal HDD / Kingston SSD 128gb
Thermaltake V2 Case(Dont remember the exact name)

And so, since 1 year(the pc got 2 or more but the specs are those since 1 year) i've been playing daily on this pc with no problems, battlefield 4, rainbow six siege, gta v, a.v.a, rocket league and so, no game gave me any trouble, UNTIL, one week ago, when i started noticing random fps drops on rainbow six sieges, i didn't mind it as i had the pc working like 15h that day, so i just let it rest, but since then, when i have the time to play even MTA SA(GTA San andreas online) i get random fps drops to 1-8fps for like 1 second(doesnt take long) each random time(between 30 and 400seconds) but basically is that, for over 1 year with the same specs and things i hadn't any trouble with any game, now, suddenly, i start getting fps drops WITHOUT changing anything on the pc, just from one day to another
I'd like to get help about whats going on, what should i do, what's wrong with the pc, do i have to change anything? Thanks in advance <3