You have excellent swing speed for the time you''ve played.
However, it's all translated into pure topspin with little ball speed, so if you relaxed more, and swung FASTER, the result would only be more spin without adding any ball speed.
Not saying it's a bad stroke whatsoever, but be aware you won't be hitting many forcing shots and winners with your forehand. Right now, it's a rallyball forehand only, forcing you to run and cover more court since you aren't hitting forcing shots against 4.0 level players.
And of course, I can rally with a 5.0 pretty even if they hit somewhere I can reach, but I would lose to a quick, athletic 3.5 singles player in a real match.
Rallying and playing points are two entirely different animals.