A good and useful expression is “恨不得”, which means "if only" or "I wish I could". 恨不得她在我身边。

"i wish i "means “我希望..”or “如果..那就好了” "i wish i were you"means 如果我是你就好了 "i wish i had more time" means 我希望我有更多的时间 I hope my answer could help you!

You can say "我希望。。。" Wish means " 希望、祝愿“ , it's some unfinished or can not be complete desire. e.g. 1. 我希望你可以放下工作，多花一些时间陪爸爸、妈妈。 2. 我希望你天天做饭为我。 would means "想要” in Chinese, it's will, like, intend to, desire, be able to, or euphemistical request... e.g. 1. 她说她会过来。She said she would come. 2. 我希望你别再喝酒了。I wish you wouldn't drank any more 3. 这个房间可以坐十个人。The room would accommodate 10 people 4. 我想要一些咖啡I would like a cup of coffee. 5. 你可以明天过来吗？Would you please come tomorrow? 6. 我告诉她别讲话了，可她就是不听。I told her to stop talking, but she just wouldn't listen

Personally, I always say "(如果)我。。。就好了". For example, "I wish you were here now" 你现在在这儿就好了。Anyway, it is 100% correct when you say like this. By the way, 恨不得, is a strong expression. Maybe it is not a proper one for your expression in English.

我希望我...