Why my fingers so extra ordinary...?

Last week, as usual, i went to my piano lesson... this time, my teacher taught me D7 chords.... there is a black key to be played..... hmm... i find my finger, a bit too fat and very difficult to play in between the black key.... and also... my finger, esp the shortest one, very weak.... not enegry to play the key... those 2 are not the major problem... as can be trained.... the most important is my last finger is very short... very much shorter than my 4th finger! aiyo... why ho? see this....
How to play like this? aito... should i give up for the 2nd time? i gave up once already le..... and this time, i really have the heart to learn le :(