dont't be upset with the result as OSCAR test is NOT 100% accurate. Let me share with you this incident - it does not happen to me but to my sis-in-law who gave birth to a baby boy one month older than my daughter.
She was really thrilled when she knew that she's carrying a boy as she had a girl already. Like you, her OSCAR result was unfavourable. Hers was 1:240 and she is just 35 yo (I am few years older than her and the ratio for me is 1:2429). She was devastated and cried her lung out. I consoled her and we encourage her to seek 2nd opinion; which she did.
The other gynae adviced her to take amniocentesis test which of course has a 5% miscarry but she decided to do as 'amnio' test has 95-98% of accuracy.
Anyway, the 'amnio' result came back few days later and confirmed that the baby is healthy. The baby was due in May and weighed 3.7kg upon normal delivery. He is a healthy and cheerful 5 months old now.
What you might want to ask yourself is - do you want to risk having a down syndrome baby? or do you rather take that 5% risk of miscarry but know that your baby is 100% normal? If you do not want to take 'amnio' test, would you keep worrying until the baby is born?
Whatever decision you are going to take, remember OSCAR test is not 100% accurate. Take care and God bless.