The differences between ‘while’ and ‘on the other hand’. Can they replace each other?

My dear parents I consider my parents really set a good example for those young couples.They have married for almost 23 years,but they are still loving each other deeply! My mother is an outgoing and live person. and sometimes she is easy to get irritated.While my father is very gentle and considerable! I suppose that it is this opposite character that makes their marriage successful! My mom is good at cooking,she can make delicious dishes for us.I think that it may be another factor for their happy marriage,coz her cooking has successfully satisfied my father's stomach...haha.. Mother always tells me that until she met my father,she did not believe the fate.So I do believe I will meet the right person one day,I'll be waiting for him silently!!

First notebook entry: Introducing myself Now,i'm learning English,because i need to pass the ielts ,then i can enter my ideal university to study further!! My mother tongue is Chinese, and i live in Wuhan which is called "university town" in China..There are various tasty food in my city,welcome to my hometown!! My major is finance ,and i'm an amateur dancer,dance is my love! I hope i can make friends from other countries through italk,and we can learn from each other,dear friends~!