Lines that I couldn’t understand:
I pray thee mark me: I thus neglecting worldly ends, all dedicated to closeness, and the bettering of my mind with that, which but by being so retir’d o’er-priz’d all popular rate: in my false brpther awak’d an evil nature and my trust like a good parent, did beget of him a falsehood in its contrary, as great as my trust was, which had indeed no limit, a confidence sans bound. He being thus lorded, not only with what my revenue yielded, but what my power might else exact, like one who having into truth, by telling of it, made such a sinner of his memory to credit his own lie, he did believe he was indeed the Duke, out o’ th’ substitution and executing th’ outward face of royalty with all prerogative: hence his ambition growing: dost thou hear?

Soft sir, one word more. They are both in either’s powers: but this swift business I must uneasy make, lest too light winning make the prize light. One word more: I charge thee that thou attend me: thou dost here usurp the name thou ow’st not, and hast put thyself upon this island, as a spy, to win it from me, the Lord on ‘t.

If anyone can help me understanding these 2 lines, that would be great.

Lines that I understand:
Dull thing, I say so: he, that Caliban whom now I keep in service: thou best know’st what torment I did find thee in; they groans did make wolves howl, and penetrate the breasts of ever-angry bears; it was a torment to lay upon the damn’d, which Sycorax could not again undo: it was mine Art, when I arriv’d, and heard thee, that made gape the pine, and let thee out.

That stupid slave, Caliban. You know what kind pain you were in. your groaning made wolves and bears suffer. It was a pain that cannot be undo because Sycorax died. It was my magic that when I arrived, I heard you and I opened the pine tree and let you out.

If thou more murmur’st, I will rend an oak and peg thee in his knotty entrails, till thou hast howl’d away twelve winters.

If you speak one more word, I will put you in an oak tree and keep you there for 12 years.

These are questions that I thought while reading act 1 scene 2:
Is this scene based on other stories like myth or is it just made up?
Why did Shakespeare made Caliban speaks poetic?