how to take away the dead animal taste/smell from meat?

Cooking the meat, marinating the meat will remove the raw smell from the meat.

You can try different kind of meat; beef, pork, chicken... they all smell different.

If wanting to add meat back to your diet, do it slowly and try finding recipes that you can add little bit of meat at a time (mostly stews and sautées) before going full on with a t-bone steak.

Avoid cuts like liver that naturally have a strong flavor. Start slowly with lean cuts like chicken breats and tenderloin and use a lot of spices.

Chicken and pork are good cuts for marinating a few hours before cooking. An acid marinate will naturally remove any odor or unpleasant taste.

It is indeed "in your head", which is absolutely normal. All tastes, good and bad, are in our heads, as well as most other things we experience. Taste is subjective, as are the associations we make with a particular aroma, and the general attitude we have towards an aroma (in your case, aversion).

If you want to start eating meat again, it shouldn't be too difficult to reestablish a positive attitude towards meat and start perceiving it as "tasty" as opposed to "dead animal, yuck". It is a very common attitude in humans, and there is some predisposition to like the taste, while the dislike usually has to be acquired. However, it will take a bit of time and training.

When you do this training, the last thing you want to do is to use tricks to distract yourself from the taste or mask it with marinades, spices or whatever. This way, you won't be training yourself, you will be reinforcing the aversion. On the contrary, you will have to make yourself experience the taste while being present, and try to explicitely acknowledge any unpleasant feeling or thought that comes with eating it, now and then asking yourself "is it really that bad". You will probably want to start with small doses, maybe one bite of meat per day. With time, you will relearn to enjoy it, but not if you shield yourself from the experience while you eat it.

I think any/all of the following will help:

• choose meat with the longest possible use-by-date
• use the meat ASAP after purchase
• clean and dry meat before cooking with damp and dry paper towels
• start with less flavourful meat like chicken
• pan-fry it on a high heat so that the dominant aroma is toasty browning/caramelized/maillard products
• use cured or brined meat (or do it yourself). This will control microorganisms contributing to the smell
• before using actual meat, start training your nose with small amounts of clean-flavoured cured or fermented products like thai fish sauce, oyster sauce, bonito flakes maybe worcestershire. Going to your local asian supermarket and buying the most expensive one you can find is really going to help.
• eat small amounts with vegetarian/vegan fermented products like miso paste, soy sauce, wine, koji, natto, tempeh.
• miso soup

Good luck!