I had heart ablations done in aug. Of last year. Didnt work. Now I can't breath just from walking. Get dizzy, pass out, chest pains. What could it be?

New arrhythmia. there is a good chance you have other abnormal heart rhythms. ablations often don't work, or need to be redone, or other arrhythmias develop. you need to get back to the heart doctor.
Time to get to ER. Um, which one of those symptoms would you ever consider "normal"? If you can't walk around and breathe, if you pass out, if you get chest pains, you should go to the er for evaluation. It is highly likely there is a problem present that should be found and addressed.