Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
I'm sorry to hear about that... even if the broken-off part were removed with tweezers, it is quite possible that the jack is broken, from the strain of having a plug broken-off in it.
If you cannot find a speaker set with a USB jack input, you are out of luck, until you get a laptop tech to open the laptop up, unsolder the broken jack, and put in a new one that will make it work again (as well as checking the circuit board for cracks and hopefully testing it before handing it back to you as 'fixed'.)
Should I search for a speaker set with USB input? if so, let me know - such a search by me, at this point in the case, will cost you nothing extra in the way of JustAnswer.com charges, I assure you.