It's completely normal to have difficulty in questioning your reality, when in a dream
The reality of the dream surely makes it harder to pick out discrepancies (when you remember to)

So, as you said, whenever doing a reality check - assume its a dream until you prove otherwise. And make sure you do a few checks, not just one.

As for the blurring of reality/dreams, that happens to some people for a while. Another side effect is not being sure when a memory was just a dream, or a real memory. You get used to it after a bit of time, and its not a permanent problem IMO