There are a few possibilities due to which you might be facing this issue. First, as you mentioned that you bought the guitar six months ago and are trying to learn via YouTube, it is possible that you haven't yet developed the required finger strength which is very common among new players. Second possibility which I think is very likely the cause of your problem is that you might be using a set of heavy gauge strings which are generally harder to play. Try using low gauge strings like d'addario extra light or maybe Ibanez extra light or fender etc. Go for 0.009 to 0.045 guage strings. Third possible issue can be that your strings might be far away from fretboard. This might be fixed by adjusting the elevation of your guitar bridge. It can be also be due to some upbow which means that your guitar neck is bent outward moving the strings far from frets. This can be easily fixed by adjusting your truss rod. If you can't do it, seek help from an experienced guitar player or a professional.
I really think that the problem is with the guage of your strings. Try using low guage strings.
Click a photo from the side of the fretboard so that the distance between your guitar strings and frets is visible.