Dr. H. Glenn Conrad compiled "A Bibliography of Louisiana Parish History" (Occasional Publications of the Friends of Sandel Library No. 1, University of Louisiana at Monroe, 1999) that you might can get through interlibrary loan. It lists a number of sources of every parish but a couple for Lafourche is Edwin C. Bearss, "The Civil War Comes to the Lafourche" Louisiana Studies (1966), Helen Margaret, "Bayou Lafourche" (M.A. thesis, LSU, 1968); Tanya Brandis Ditto, The Longest Street: A Story of Lafourche Parish and Grand Isle (Baton Rouge, 1980); Philip D. Uzee, The Lafourche Country: The People and the Land (Lafayette: Center for Louisiana Studies, 1985).
For Terrebonne, two are Phoebe Chauvin Morrison, Pioneers (Terrebonne Genealogical Society, 1984), Marguerite Emma Watkins, "History of Terrebonne Parish to 1861" (M.A. thesis, LSU, 1939). Most of those listed are genealogical sources.