Did I commit big mistake by using wrong engine oil ?

No. No big deal. I wouldn't worry about it. However, I would drain the oil out and add the proper type of oil but your engine will be fine!

You should be using 5w-30 synthetic in that car. You run the risk of damaging the oil pump in various ways due to the extra thick oil it has to try and pump.

Drain it immediately, it could blow your seals.

Manufacturer's recommendation. But these, surprisingly (or is it?) vary by model year and country for the same engine. My 2001 Camry says 5w-30 on the oil cap, but 10W-30 is optional according to the manufacturer. Oil recommendation for the same engine some years past was 10W-40, and in another country 20W-50. I plan to check and see if the bearing clearances were different in earlier models before I conclude I can use a heavier oil. In the United States manufacturers recommend thinner oils to help them meet fleet economy standards. But these may not be best for the engine. If anything, it is probably better to use the heavier weight oil but not beyond the manufacturer recommendation. The newer the production, the more sensitive the engine might be. You have to do your research. A major function of oil is the protect canshafts from wear. Even though it is the same engine, the manufacturer could change the alloy the camshaft is made from or use a different surface treatment, and that could determine what oil is recommended. Particularly, 10W-40 is different from a 5W- or 10W- 30 oil. 10W-40 contains less base oil and more additives and vicosity improvers. It is made for American cast iron engines of the pre-1980's era. You can use just about any oil in these consistent with the temperature where you are, including straight 30 weight or even straight 20 weight in a very cold climate. Not with later alloy and bimetal overhead cam engines.