I'm going to be devil's advocate and pull a "no, don't do it."
HOWEVER, I'm not saying this because I don't you'll be capable. IMHO, if you've been disadvantaged this much over the year (and assuming you'll still be recovering next year - I know how much painful eye problems can be, and it sounds like you hit a beauty of one), maybe you should do year 12 over two years. In which case, if you do year 12 over two years, I reckon it would be better to put off specialist for the next year.
That being said, if there's some particular reason you're not doing it over two years (eg, already done two 3/4 subjects), then go for it. Not knowing all of methods won't be too disadvantageous - it'll be an issue if you're not caught up by term 2, but otherwise the courses are quite different, and you'll probably find doing specialist brings you up to speed for methods, rather than the other way round.