A question about normal maps

Hello, i am totaly new to this kind of stuff and allso to unreal. I am right now trying to make some simple materials. So my problem is this: I googled some textures of rocks 1024x1024 i allso googled about how to make normal maps from that texture file, i found out you could use this site NormalMap-Online and you could use a plugin for gimp. Well i used some textures i found and from that plugin i made this “normal map” and i allso tried it on that webpage in the link. But when i apply this normal map in a material and put that material on a wall in unreal everythings get noisy when i play, its like sparkles of lights all over the wall and shadows of my movement fades in and out on the wall. So offcourse is my question what am i doing wrong here? or what have i missed? everything else looks ok and i can get the pattern on the wall but why am i getting this strange result? i tried all of the normal maps from the starter content and there are no such effects at all in them. As i said i am new to this and not so sure myself what a normal map is, i do understand why they are used then. I looked at some points on the included normal maps when i opened them in unreal they got something called mips? but on my maps there are no such things lol sorry i dont even know what that mips is.
So i would be glad if somebody could tell me what i do wrong.

Screenshots help material, normal map, texture, and final result.

Hello again. Well i had some problems taking a screencap of the effect. What i i did is i downloaded a program called crazybump, and after that the result getted better, but still i have this effect. I try explain the effect the best i can in english, i am not very good in english but…
when i stand infront of my wall with my material on and if i move my head (rotating) i can see for a short second a fading picture of my chars head on that wall (3rd person). I actualy did study how the normal maps included in unreal behaved and now i can see i allso get this effect from them but very very little, and allso from this crazybump the effect is more less then from the gimp plugin, i now guess its about my computer and that normal maps takes more power then just plain texture files? no idea. I am new on this stuff as i said just interested trying something new.
I send the texture and the normal i made from it if any one want to try it and see if they get same effect.

sorry did not get the normal file in same post but here it is 9bd4c2f663092ca9530f3bd2fd42e103c8ba122f.jpeg

Can you post up how you have set up your material. Also make sure the normal map texture within the content browser is set to Normalmap compression. (Not sure what it is called exactly this version)

then grab a video