夏季休暇はまだまだ

Other people's summer vacations started since today. Other people started their summer vacations today.

I don't start my summer vacation at this week.My summer vacation doesn't start this week.

I'll take a two week late.I start two weeks late.My summer vacation starts two weeks late.Mine starts two weeks late.

I wrote a few alternative corrections that you could use depending on context.

I feel so very hot,I'll keep trying hard so today.I feel so hot. I'll keep trying hard.

I'm not sure what the connection is between these two phrases, so I broke them up into two statements. The "very" in the first statement isn't incorrect, but it sounds a bit awkward.