[Zenthachall]

Hi, Vire.
What I would recommend is that when you're at the point in which relaxation exercises are causing hyperawareness of body sensations (which is what I think is going on here) instead of continuing with the same type of exercises move to a type of exercise which promotes relaxation but doesn't involve the body itself: Possibly visualizations with breathing, or other things I'm going to try to list (if I can remember them.)
1. Chakra breathing- On the inbreath imagine there is a hole in your crown, and the air is coming in through it. On the exhale imagine the air has traveled through the middle and is coming out of an imaginary hole where your brow is (third eye chakra). Repeat the head-inbreath thing and go down your body on the outbreath, in this order: throat, heart, solar plexus, groin, bottom of feet (heels). This is just for starters.
2. Balloon breathing: Imagine you are breathing in pure white light. On the exhale imagine you are breathing out darkness. Do this a few times until you get bored of it.
3. Imagine you are walking along a path in the woods. Just look around the imaginary woods as you walk, do it slowly, taking in the scene. If you want to, imagine the path becoming just slightly higher. You can take this as far as you'd like, nothing is 'wrong'. I usually like to end up in the top of a mountain, for example. Have fun with it.
4. Color watching. (I "invented" this one, and doesn't work for everyone). Do basic breathing with your eyes closed. Observe the color of the space in front of your eyes. (Most of the time during the day you'll see a color that's pinkish, not unlike what happens to playdough when you mix all the colors.) Observe the color blobs in front of your eyes. At night it may start out black, but you will soon see color here and there, due to the retinal cells firing due to the lack of light. If so, just observe the color blobs.
Soon you will realize that the pink/gray/or whatever you see is a mixture of tiny pixels of different colors- now the fun begins. Start by trying to see red. This is (for me) the hardest color to pay attention to, but if you started with pink you can 'find' the red pixels and try to turn the blob to that color. Once you've succeeded move on to the next one in order: orange, yellow, green, blue, and violet. Violet or purple are usually easy, you might find. If one color doesn't want to manifest, don't sweat it, move on to the next.
5-If you find yourself tensing up, go back to progressive muscle relaxation, and when you're done, go back to a more mind-centric exercise when you're done, and don't worry about anything relating your body.
6. Noticing. I leave this for last, for when I'm almost ready to go. Usually you just observe the space in front of your eyes (like in the previous one) but you don't try to 'see' anything, just observe. This can be uber-boring, so I like to listen to my earhiss at the same time. I find that dividing my attention keeps me busy enough and eventually the listening resolves the hiss into discrete sounds. When this happens I know my mind is synching with my brain as it goes down to theta, and I'm closer to the stage for a successful exit attempt.

Good luck, I hope this helps.