I have a hard time making my mind with Mathematics. Please help?

You need to look up the meaning of "arduously !"

[You should look up "assiduously," too]

Let your interests take you wherever...

It is not possible to learn ALL subfields of anything.

But, get checked for bipolar disorder !

nothing wrong with you

good - people with passion only can achieve something or master a subject like maths.

steady yourself a bit go topic by topic and master - most of the maths topic are interlinked and it will help going about them item by item absorbed well and enjoyed.

I am not sure what you mean by short time and mastering all subfields of mathematics - the subject has the potential to consume years of your life if not a life time

While your eagerness to learn is admirable, it really isn't possible to completely learn every area of mathematics. I don't say that to belittle your ability, I say that because there isn't a single mathematician on earth who has mastery over every area of mathematics. It's just too vast of a subject. Mathematicians come in two varieties, there are generalists and specialists. Generalists have a broad knowledge of the subject as a whole, but they don't have expertise in any particular area. Specialists have one or two specific focus areas that they contribute to as a researcher. If you really enjoy all areas of mathematics, maybe you are destined to become a generalist. Although, if you do find a specific area of mathematics that you feel drawn to you may decide to specialize in that. Bear in mind that if you take that route, you almost certainly won't know what your preferred area is until grad school, so there's no need to rush things.

You are just young and excited. Enjoy it for all its worth. Yes you can learn all the subfields of math, but you will have to learn discipline at the same time.

Try practicing in workbooks and go online...Use calculators and try remembering math songs... I know it sounds like a kid thing but songs do help....Even try kid problems