No, you do not have to wait to sell the shares you purchased two weeks ago. Wash sales occur if you rebuy the sold stock within 30 days of selling it. Selling additional stock within 30 days does not trigger a wash sale.
If you were to rebuy IBM stock within the 30 day period following the sale, then that loss would be considered a wash sale. It does not matter which brokerage account you purchase the stock from. The brokerage you sold the IBM stock would know that it is a wash sale and treat it appropriately on Form 1099-B. If you bought the shares at another brokerage, they would not know that it triggered a wash sale and the onus would be upon you to report everything accurately.
