I have sleeping problems and an iron deficiency. recently my body feels really weak but im not sleepy. which problem is causing this symptom?

Too many choices: For sure - anemia can play a role - but beyond and behind that - too hard to guess. See your provider for a solid exam and lab work. Then, with the result, take it from there. Not reason to guess and that route can be a source of problems if it generates health anxiety. Find a good Dr for a good 'work-up'. I hope it goes well and you feel better soon.