Been diagnosed with SAD two years ago but dont know if i have it

Hi All just hoping someone on here can help me, im only 19 but have suffered from depression since my early teens.

I ve been through a family breakup etc however that was 5 years ago and after it was all sorted i quickly moved on.

My depression is worse between october and march however last year i was out in the middle east from august till end of oct and still got depressed beginning of october, the time of year has come around again and im feeling depressed again, Im just wondering if i actually have SAD or not.

I find it hard too sleep i ve lost my appetite partly i keep on getting confused and forget things that i usually easily remember. I also keep on having bad dreams which quite often scare me with the content of my thoughts in them.

Hope this makes sense and any answers will be great as i would like to get to the bottom of this.

Thanks

Ed