Concentrate in the HC110 example is the thick, viscous, yellowish syrup that you get directly from the manuafacturer.
Now, there is working solution which is the diluted concentrate that is ready for the tank. Look on the bottom of your tank and see if it has capacities.

Your stop bath procedure sounds fine except that it would be preferable to have an acetic acid solution but if you only have water then maybe do your 45 second thing twice with 2 dumps of water. That will help your fix last a bit longer.

Kodafix has 2 dilutions. One for paper and one for films.
If my mind doesn't fail me I think the film dilution is 1:3

Dont give up or despair
It gets really easy after you have your process down and you will be quite pleased when you take control of your entire image.