Hello,for some reason,i've started to experience insomnia for days straight,like when i try to relax and sleep,my heart keeps on pouding and my mind finds something that would worry me, i also experience brain fog and weight loss, is this deficiency?

It is not feasible to provide an opinion without additional history, physical examination may be some tests. It would be prudent to see your doctor to see if you may be depressed. Depression is treatable. Counter-intuitive as it may seem, exercise may help. Start with low intensity exercise such as walking and gradually increase the intensity as tolerated. Drink more water. Wish you good health!

Unable to provide a simple explanation, as your doctor will need to do some testing. But sounds like the insomnia is secondary to anxiety and worry, and indeed depression should be considered. The "brain fog and weight loss" are likely secondary. Some cognitive-behavioral therapy may provide assistance, and a sleep hygiene program should be used.