Yes, at 12 hours it is much more psychological and mental than physical. You will just have to focus on what you will gain by fasting rather than the deprivation. And hours 22-26 and then 44-50 could be even tougher. Just know that and prepare for it. You are stronger. Many of us fight this off and break through. The third and fourth days are smooth sailing. Its getting past those troughs and waves that are the key.
Water, particularly electrolyte waters and carbonated waters, along with salt are your friends. Try drinking some dill pickle juice as well. So is activity. You don’t have to be physically working out (but it helps), just keep occupied.
Even watching TV can help – just make sure the program provides engrossment and not mindless crap like most sitcoms. Binge watch something on NetFlix or Amazon Prime. Opt for movies with a complex plot that will occupy your mind for two or more hours. As you can see, a lot of mind games at play here.
If you’re not a movie or TV buff, there is always a good book. Even sitting and reading all these posts about fasting on this forum can occupy time and give you insight as well as encouragement. Avoid the threads involving foods and meals.
For example, I bet you haven’t thought about food while reading and digesting this reply.
Remember, your brain is sneaky when it comes to wanting you to eat. It makes excuses and reasons with you as to why you should break your fast. It even justifies overeating. But you can consciously prepare for this onslaught. Just by knowing its coming your way is power.
Good luck with your fast. By the way, I am in hour 44 of a 72-hour plus fast and it is a bear right now.