Hi, Sounds like you don't have proper placement, or don't warm-up, or abuse your voice (improper technique)?

Your voice should be good after about a 10 minute warm up/vocal stretch. My warm-up is mostly muscles like bull frogs/tongue stuff with little-to-no vocalization.

I do this everyday before I talk after I wake.

When you sleep your throat muscles tense up.

I sang with grit for 3+ hours so far today and I feel good.

The only thing that happens is that after a while it's harder for me to get above C6.

Thanks Chris for advice, I definitely need to do some more warmup (maybe I do that, but do not know about it ) The techniques I use for now is from my vocal coach but as I said soon after studying Jaime´s book I´m going to focus on his excercises. I usually begin my routine so that I stick my tounge behind teeth, making smile and singing Rrrrrrr going gradually higher and then coming back to thge initial tone (I don´t know how to better describe it) and after one repetition I move above one tone higher (I´m a beginner so for now I know nothing about notes). I should warmdown my voice but I don´t know what is the best warmdown. I must do something wrong
Do you recommend me not trying to go that loud when hitting the midle range as I feel that my voice is not in proper shape so that is hoarsy (only in the middle range)? I know my voice has troubles fully recovering from the sleep and some damage it goes through, probably sinuses are dried or little acid comes up.
Also I forgot to mention that I don´t drink, don´t smoke either, and humidity in my room is around 60 % Do you think that singer should by a decent humidifier even though the humidity in the room is around 60- 70.
I definitely need to fix this problem with some hoarsiness and cracking in my voice, I´m in a process of establishing a rock band in the style of 80s, producing many songs yet without instrumental, but soon the group work begins

Any idea on what to do before going to sleep in order to assure that your voice won´t go through drying during the night or morning causing unpleasant cracking during morning and even during halftime in the afternoon?

You can feel fatigued after hours of singing but you should never feel hoarse unless you are sick.

Can you do grit for hours without killing/tickling your throat?

If you can't then you don't have proper placement/prop technique.

I know many singers who have sung for years and had many teachers, paid gigs, but they manage by singing light and STILL lose it after a few hours and do NO grit.

One of these includes a university professor who specializes in Opera at a music school. She said the max she sings for is 20 minutes and then takes hours rest. That has to be improper placement.

Thanks Chris for your reply.:) 3 days ago I found solution. I began to flush my sinuses with the small watering can I bought from store being similar to neti pot, and it did wonders to my voice. Just like Jaime wrote in his book when he thought he had nodes and then by flushing sinuses the problem was gone! Also my morning voice recovers fast enough.