What is the difference between "particularly" and "in particular"?

"In particular" can be used as a sentential adverb, in the same way that "yesterday" can be.

Particularly can usually be used as a sentential adverb (but "in particular" often sounds better in these situations):

• In particular, I eat bread at lunch and dinner.
• Particularly, I eat bread at lunch and dinner. (Works, but "in particular" sounds a bit better)

On the other hand, particularly is used to modify an adjective (or adverb) directly, and "in particular" cannot do this. Compare:

• I did particularly well on that exam. (Modifying an adjective, "well")
• *I did in particular well on that exam. (Ungrammatical)