Well ... Absolutely sure? Pretty sure. If anyone could do it, it would be him, but I don't think you have anything to worry about. From your description, it was the contact of your wands and your close proximity that allowed him to make the attempt.

If it were that simple, Harry, he'd have tried it back when he wanted you to make your own horcrux.

The nightmares are normal. They should fade in time. Though if they get stronger than that, be sure to say something.