feeling low

Feel a fraud for grumbling cos I've been lucky but just can't seem to get my head sorted. had 4 rads sessions now & at today's I just burst into tears when nice young man asked me how I was doing! Think it's all just hit me & the thought of going through that for another 19 times is more than I can cope with. just need some strength from somewhere & a kick up the backside maybe to get me sorted! did anybody else feel this way or am I just driving myself crazy ??