Not getting what prayed for

How do you deal with praying for something so long and watch other people who don't even want it get it?

In my case it is twins. I prayed so long for twins, I had my first singleton, continued praying even after not getting pregnant and waiting for months and finally I got pregnant and again, a singleton. Am happy I finally got pregnant but am also hurt it is one. I dont want twins because others have them. I always have wanted twins. But over the years watched people around me get what I want and it makes it even harder for me to cope. I know his plans are best and I should appreciate what I have, but it is still hard. Sometimes I feel like it is a punishment. Why was I given such a strong desire and then only have to live my life seeing it not come true.

Update: thanks everyfor your comments, advice, reminders. Am so glad I posted. Have been reading everything closely. So I have good news. I am finally over obsessing about twins. I know the wish is still there but am finally happy with my one baby. I thank God because he has been working on me through sermons, his word and counselling. Also I got to finally see my baby and it is healthy and growing fast. Please continue to send your advice because I still need to learn contentment and being happy with what God gives me and wills for my life. I pray you all get your desires or what God has planned for you and that it might bring you joy.