What training course is it that you're registered on? If it's buttercups then that's normally OK to transfer to a different pharmacy if you did want to look for another job, you could always email them and ask.
Alternatively are there any other pharmacists working there who could give you a bit of mentorship. I've worked as a locum where I spent an hour every Tuesday morning running through OTC products with someone who didn't have any confidence. She'd pick a 'topic of the day' eg creams/cough mixtures and we'd run through the important differences, ingredients, indications etc.
And it's worth finding your own dispensing style. The SOP doesn't work for everyone's brain. Some people tick the box, finding each word on the script on the box, then tick the quantity and the expiry date. Others tick the script. By physically ticking you're ensuring that you've checked every word.
Finally double checking everything before you hand it over. As a dispenser, this normally involves picking into the basket, using the script and never the labels. Dispense from the top of the script, checking each part - drug name, strength, form, quantity, expiry date. Putting the label in and lining them up neatly. Then check them again (I start from the bottom of the script as it reads like a new script, meaning I'm more likely to spot an error) and sign the box as you put them into the basket. Finally, as you place the script into the basket, double check name and address on each page against the bag label.
This is how I dispense/check a prescription, everyone is different, but have a read through and think about how many times yours checking your own work, and how you're going to cope if you get distracted halfway through. Are you just going yo carry on, or are you going yo go back to a certain checkpoint.
Good luck, it's a tough job, probably going to get tougher, but it is satisfying, it switches on your rain, you're part of a team, and some of the customers are lovely!