I can relate to this. :) But with me its happening on a less serious level. I sometimes also don't notice hunger/thirst, or don't know how I got bruises, or feel pain on a very weird/distant level, stuff like that, but that normally happens when I am in a lot of mental stress and just automatically disconnect from my body. Sex is very difficult due to this disconnect, especially because I don't feel libido/desire and don't feel how my partner touches me. It just doesn't reach my consciousness. I rarely experience it how it should be. In the past I thought this is just how it is, and that I am probably just asexual. But when I calm down and lay down in my room without any distraction, I can actually feel my body very well. It's come to the point that I can even sense my hormone cycle if I want to, I can feel when my period is approaching for example (of course that's only possible when I am not on the pill).
I would recommend meditation. First just focus on your breathing, concentrate on how it enters your lungs and exits it again. Remember that you have bones, tendons and muscles, that you have blood flowing through your body all the time, that your heart beats and that your body is a living thing that always tries to keep itself alive with everything it has. It is your friend, it is nothing to be afraid of. In daily situations like drinking for example, focus on how the cold water flows down your throat into your belly (if you can say it like that haha). Or when you massage your hands, focus on how your muscles begin to relax, ect, ect. Or when you are tensed up and alert, try to notice how your solar plexus feels like - try to loosen the tight feeling in your stomach. In general, it just helps me to concentrate on my bodily functions like breathing, but sometimes I begin to feel detached again because it is just weird to become aware of your body. We are not used to that. I mean, how often do you focus on your digestion? :D Or how often do you think of your brain?
Also, feeling your body can sometimes be too much because it triggers memories. So I would just try to begin feeling your body in a safe place, as
@littleoc suggested already. Do it step by step, always just as much as you can take, and if you feel like you slip away due to dissociation, try to ground yourself again. Have scents nearby or touch some interesting fabric, or listen to sounds in your environment. I hope that will help! Don't give up, just do it regularly! When feeling your body slowly becomes less frightening, you will automatically begin to sense its needs and cues. I think you have to strengthen the link between a feeling of safety/security and the feeling of being present in your body. This will weaken the other link between feeling fear/anger/sadness/whatever you felt during your trauma and the feeling of your body. I guess your body just remembers a lot more that you consciously know and maybe it wants to protect you from these memories. But by slowly and patiently working through these knotted and painful body memories, I am sure eventually you will resolve them and find peace.
