What's going on with me at work?

Not sure what's going on for a while but Im noticing that my pace is slower only at work. I want to better myself. I need your advice. I've had so many jobs and most recent one I unfortunately got fired. I used to work for a non profit for so many years I loved it and was praised for my work I was an Administrative Coordinator. I left that job 2 years ago to go abroad and now I'm at a new job and will soon be hired permanent. It requires alot of Data entry which I tend to slow down on and I don't do it on purpose I'm a good worker and Im praised at other tasks which is why I'm getting a permanent position. I want to enhance my skills and I can practice my data entry but i tend to see others be more ahead of me. Like today I had to input data entry it's taken me 2 days and gal next to me took her 2 hours! I couldn't believe it I was so embarrased and my manager noticed it and appointed it to me in front of everyone.This job will start for me in two months and I don't want to disappoint my manager or anyone. I remain positve and I'm willing to do whatever it takes. I have a family to attend to and would be devasted if this worsens. Please advise me what should I do to enhance myself?(Yoga, Medication, I've heard this help memorization ect)