With theOver time, I learned how valuable is to sleep well. Over time, I learned how valuable is to sleep well.

With the time, I learned how valuable it is to sleep well. With time, I learned how valuable it is to sleep well.

No article with "time"

I hate it a lot when I am exhausted or with headache during my day. I hate it a lot when I am exhausted or with headache during my day.

If you have a modifier (like "a lot") between "I hate" and the thing that you hate, then you need to put in an "it" as a stand in for the subject of hatred.

I hate a lot when I am exhausted or with headache during my day. I hate a lot when I am exhausted or with headache during my day.

"my" could also be replaced with "the"

So, to takeaking Melatonina during sleepless nights helps me a lot. So, taking Melatonina during sleepless nights helps me a lot.

But, I need to be careful with the quantity, or if nottherwise I can obtain the contraryopposite effect. But, I need to be careful with the quantity, otherwise I can obtain the opposite effect.