Then it's similar to my case. As long as you didn't work during the part-time semester when you finished the courses you failed, you might still be okay.
Not sure if you worked in your final semester but if you didn't, you can explain to the visa officer (in your LOE) that you didn't work during your final semester and dedicated your entire focus to finishing your program. This is what I did, but you could also explain why you failed the courses or why you couldn't retake the courses along with your co-op.
Hope to see a positive update from you!
