I am afraid I will forget. Can I read the qabul from a piece of paper during the akad?

Yes; the qabul does not have to be memorised, as long as it is said clearly and follows straight after the ijab. What makes the akad valid is words that the wali and witnesses understand, not how you remember them. Reading from paper can, however, cause a long pause while your eyes look for the line. Practise several times before the day, and ask the marriage officiant which wording will be used. Most officiants guide the groom and let him repeat the words if he stumbles. Take a breath and stay calm; small mistakes can be put right there and then. See a valid ijab and qabul.