Persistence (non-physical)

Hello Rabbi.
I have a very hard time persevering in something for a long time. Whether it’s regular studying, playing music, writing, or even just cleaning my room. Every now and then I do things in spontaneous bursts (finishing a treatise/studying for a final exam in two days, cleaning every corner of the house, etc.), but I don’t manage to do it (even in much smaller doses) on a regular basis. In short, I know how to persevere in two things: in trying to persevere, and in failing at this attempt (what’s called second-order persistence). Every once in a while I decide for myself “That’s it, from now on you start doing X every day,” and after a week at most I go back to my old habits. There’s a kind of element of weakness of will in this, at least in terms of feeling (I know I want to persevere but in reality I don’t), which only adds to the feeling of frustration.
My question is: How to persevere? And more specifically – how do you persevere, and deal with the difficulties involved? (It is clear to me that this is a very amorphous question and it is difficult to give clear instructions, certainly without personal acquaintance. General guidelines and ideas that helped you would also be very useful to me)
I have hoped for your salvation…