Man we told you not to take clen, but you are going to do it anyways, and you want us to help 8). I am only going to give advice in the name of harm reduction, not because I think that you should be using clen.
I am guessing that your clen is 20mcg, or .02mg per tab, which most clen is. It should say right on the bottle or blister pack what the dosage is. I would start at one tab a day and move up 1 tab every 3 days until you get to 5 tabs a day, or the side effects are to much. You should use clen in a 2 week on/2 week off cycle and continue for 2-3 total cycles. Most people cant use more than 100mcg a day but I can use 400mcg a day and be fine, so it is just a matter of finding the right dosage for you.
You should continue the same water and diet, and training (that we have heard nothing about yet) during the clen.