Full list:
Chapter 1: Ancient Flames Beckon
1. The Rites of Life (1-1)
2. Below the Arks (1-2)
3. The Mothercrystals (1-3)
Chapter 2: The Isle of Forgotten Saints
4. An Invitation West (2-1)
5. The Lost City (2-2)
6. Distant Beliefs (2-3)
7. An Eternal Melody (2-4)
8. Ancient Vows (2-5)
Chapter 3: A Transient Dream
9. The Call of the Wyrmking (3-1)
10. A Vessel Without a Captain (3-2)
11. The Road Forks - Emerald Waters - Vicissitudes (3-3 San d'Oria-1)
12. The Road Forks - Emerald Waters - Descendants of a Line Lost (3-3 San d'Oria-2)
13. The Road Forks - Emerald Waters - Louverance (3-3 San d'Oria-3)
14. The Road Forks - Memories of a Maiden - Comedy of Errors (3-3 Windurst-1)
15. The Road Forks - Memories of a Maiden - Comedy of Errors (3-3 Windurst-2)
16. The Road Forks - Memories of a Maiden - Exit Stage Left (3-3 Windurst-3)
17. Tending Aged Wounds (3-4)
18. Darkness Named (3-5)
Chapter 4: The Cradles of Children Lost
19. Sheltering Doubt (4-1)
20. The Savage (4-2)
21. The Secrets of Worship (4-3)
22. Slanderous Utterings (4-4)
Chapter 5: The Return Home
23. The Enduring Tumult of War (5-1)
24. Desires of Emptiness (5-2)
25. Three Paths - Past Sins - Southern Legend (5-3 Louverance-1)
26. Three Paths - Past Sins - Partners Without Fame (5-3 Louverance-2)
27. Three Paths - Past Sins - A Century of Hardship (5-3 Louverance-3)
28. Three Paths - Past Sins - Departures (5-3 Louverance-4)
29. Three Paths - The Pursuit of Paradise - Spiral (5-3 Tenzen-1)
30. Three Paths - The Pursuit of Paradise - Branded (5-3 Tenzen-2)
31. Three Paths - The Pursuit of Paradise - Pride and Honor (5-3 Tenzen-3)
32. Three Paths - The Pursuit of Paradise - And the Compass Guides (5-3 Tenzen-4)
33. Three Paths - Where Messengers Gather - Entanglement (5-3 Ulmia-1)
34. Three Paths - Where Messengers Gather - Head Wind (5-3 Ulmia-2)
35. Three Paths - Where Messengers Gather - Flames for the Dead (5-3 Ulmia-3)
Chapter 6: Echoes of Time
36. For Whom the Verse is Sung (6-1)
37. A Place to Return (6-2)
38. More Questions than Answers (6-3)
39. One to be Feared (6-4)
Chapter 7: In the Light of the Crystal
40. Chains and Bonds (7-1)
41. Flames in the Darkness (7-2)
42. Fire in the Eyes of Men (7-3)
43. Calm Before the Storm (7-4)
44. The Warrior's Path (7-5)
Chapter 8: Emptiness Bleeds
45. Garden of Antiquity (8-1)
46. A Fate Decided (8-2)
47. When Angels Fall (8-3)
48. Dawn (8-4)
You're on number 18 out of 48. Though admittedly a number of the missions are just running around seeing cutscenes. Listing them off by things that actually require effort:
1. 1-2 - 1 area crawl, 1 BC, 30-cap
2. 1-3 - 2 area crawls, 2 BCs, 30-cap
3. 2-3 - 1 area crawl (including 1 NM), 40-cap
4. 2-5 - 1 area crawl, 1 BC, 40-cap
5. 3-3 San d'Oria-2 - 1 NM, uncapped
6. 3-3 Windurst-2 - 1 NM, uncapped
7. 3-5 - 1 area crawl, 1 BC, 40-cap
8. 4-2 - 1 area crawl, 1 BC, 50-cap
9. 4-3 - 1 area crawl (including 2 separate NMs), 50-cap
10. 5-1 - 1 NM, uncapped
11. 5-2 - 1 area crawl (including 3 separate NMs), 1 BC, 50-cap
12. 5-3 Louverance-3 - 1 BC, 60-cap
13. 5-3 Tenzen-1 - 1 area crawl, 50-cap
14. 5-3 Tenzen-3 - 1 NM, uncapped
15. 5-3 Tenzen-4 - 1 area crawl, 60-cap
16. 5-3 Ulmia-2 - 1 BC, 50-cap
17. 5-3 Ulmia-3 - 1 BC, 60-cap
18. 6-2 - 3 NMs (together), uncapped
19. 6-4 - 1 BC, 60-cap
(Everything past here is uncapped.)
20. 7-4 - 6 NMs (4 of which are together)
21. 7-5 - 1 BC
22. 8-1 - 9 NMs (3 trios)
23. 8-2 - 1 area crawl, 1 NM
24. 8-3 - 1 area crawl, 1 BC
25. 8-4 - 1 BC
And in that regard you're on number 7 out of 25. And yes, chapter 5 does take forever. The parts commonly considered "hard" are 2-5, 3-5, 4-2, 5-3 Ulmia-2, 5-3 Ulmia-3, 6-4 (this one's particularly nasty), 7-5, and 8-3.