Iam seriously forgetting things just lately! i dont know whats going on!? im on 100mg sertraline and have been for a while now starting from lil doeses from 25mg for 2 weeks and then 50mg, then 75mg, then now im on 100mg but i feel like i have a brain problem?

For eg.....

I put a cheque in my bank for my dad, and i wrote him a cheque to his bank as i owed him some money and then a coupe of days later i draw the money out and give it to him, and my mum said why did you do that for you gave him a cheque!!! OMG im loosing my marbles and i have no control over this!

I really think i have something wrong and i want to google but i know i shouldnt!

I dont know what to do, sometimes i want to say something and the wrong words come out! really worried!