I fail at everything

I have learning problems its hard to pay attention and to even remember anything no matter how much I pay attention, well I got a job and its a pretty good one and a home job so this week is training and I have an exam I have to pass tomorrow to move on with employment and I literally learned nothing I will fail for sure cause I can't even tell you anything about any of the training. I used to take meds and always had them switched cause they never worked so I don't even take them anymore cause they don't work for me. I have bad panic attacks and mental breakdowns where I cry a lot well everyday I cry 4 times a day during this training and my training is only 5 hrs. I don't know what to do anymore its been years with the same old same no matter what job I get it doesn't work out I go thru prob 20 jobs a year with only working a week each job. I have only a 3rd grade learning level I even tried to get ssi and I was denied . I'm outta options.