It’s OK. You don’t need to do it suddenly. Acquire the skill gradually, step by step.
Super Ardua advice is good: scales are the best place to start.
Try this for a couple of minutes everyday:
1. Close your eyes, and with both hands find the group of two black notes. You are going to play them with fingers 2 and 3. Use your touch and investigate by touch the neighbouring keys until you find a group of two black notes for the right hand, and the group of two black keys for the left hand one octave lower. It is easier if you flatten your fingers and use the full extension of the fingers (and the palm of the hand if it helps) to feel the contours of the keyboard rather than just the tips of the fingers. Take your time and make sure you got the correct black keys. Then put your hand in playing position (natural curvature of the fingers, only tips on the keys) and press together the two groups of two black keys. You can now open your eyes and check if you got it right. If you got, move on, if not try again. You can also have someone looking at you doing this, and checking for you if you got it right, this way you do not need to open your eyes. Eventually you will be able to tell by ear if you got it right or not.
2. Now close your eyes again and try to do it for the group of three black keys. Use fingers 234.
3. Once this is easy, try to go through three or four octaves playing hands together the groups of two and three black keys with closed eyes. Don’t use the thumbs, use fingers 23 for the two black keys and fingers 234 for the three black keys.
4. Once this gets easy, use the thumb to play the B (white key) and the E (white key). So, with the right hand you will be playing B with the thumb, then C# and D# together with fingers 23, then E with the thumb and F# - G#-A# with fingers 234. In order to locate the whit keys, your hands must be well into the black key area, so that the thumb can touch the black keys and find the B and the E by reference to the neighbouring black keys. This is important and you should insist on it form the beginning: It is the black keys that allow for geographical orientation on the keyboard. Now do the same with the left hand and then hands together. You are of course playing the B major scale.
5. Do this sequence for 2 – 3 minutes everyday (everyday is more important than 3 hours doing it). In a couple of weeks you should detect a huge difference. Come back for more then.
Best wishes,
Bernhard