Hi Anthi! You aren't a worrier. Your surgeon should have told you this info. Yes, you have to protect that arm. Because you have had your lymph nodes removed, the drainage that is normally done thru the lymph nodes is now compromised. Here are a few things that my surgeon told me:
..Always keep the arm covered or use good sun block when outside, esp when in the sun.
..Don't use a regular razor to shave under the arm. Use only an electric razor.
..Be careful when getting your nails done..around the cuticle area. No cuts.
..When working outside in the yard or garden, always wear a glove.
..Don't lift anything heavy w/ that arm.
..When you get a cut or bug bite, watch it very, very closely for an infection.
..When flying (on a plane..lol) always wear a special sleeve. You can get one made that is just for your arm size.
..If you notice any redness or you think that there is any swelling, contact your physician immediately.
I have to admit that I don't always follow these rules, but I try. I really do protect my arm at all costs.
Keep doing your exercises. One that I found still works is when I am in the shower, I will place my hand against the wall and walk it up the wall as high as I can w/out pain. The hot water helps relax the muscles.