Medical problems

I forgot to claim my medical expense I had in 2015, can I just add this to my2016 medical expenses?

You unfortunately can't submit both years claims on the latest return but you need to resubmit last year's return and include last year's claim on there.
You should be able to call SARS and ask them to reopen the link for you or you can just go and submit the documents at a SARS office in person.