PlEASE HELP A DYING HEART! WILL I BE WRONG TO MARRY THE ONE I LOVE?

Please read this and help me- Due to my family's financial background, a neigbhour decided to help take care of my education. He made sure I lack nothing and now I'm in my final year in secondary school. I'm 18 years old. Last month, I was trecking to extra morals when a car stopped, halting for me. The guy inside greeted me and pleaded that he give me a lift in his car. I politely refused but he insisted with pleas and I finally agreed........ We exchanged phone numbers............ Now,we're so much in love. My benefactor use to tell me about his 22 years old son who schools in Ghana. I've never seen him nor his pix until yesterday when I met my lover in my benefactor's house. I was so surprised when he told me that my helper was his dad. This guy has already asked me at what age I would like to get married and I told him at age 22, by then he would be 26 and he has already proposed to me of which I accepted. I love this guy so much, but am thinking that my marrying this guy wil be like a repayment for all the good deeds his dad has rendered to me. I dont really kno what to do. Pls help me. I would also like to kno if age 22 is good for a lady to be formally married. Tnx.