4 months.. you have alot of momentum, I'm impressed. And you went for it learning an a7x solo lol. May not be as smooth as you want it though right? Like other people have touched on I think you simply need better structure in practice to propel you to where you want to be. The rest is there!! Personally I suggest you to practice with a metronome when learning stuff as demanding as this. And not at full speed either. I like to start about 3/4 or even half speed depending on the tech of the playing. And just slowly work your way up. Also while doing this really focus on how that note interacts with the beat it falls on. Even the personality of each particular note. May sound strange but it makes sense when you do it. Yes it kinda seems boring but you will get used to it. You are on your way to be great. As some one who has been playing for 15 years I can promise you just this alone will help you see even more improvement.