Hii , I have uploaded the full code and 8 data files. Please find them.

Attachments:

data1 10 Torr.CSV

data2 20 Torr.CSV

data3 30 Torr.CSV

data4 40 Torr.CSV

data5 50 Torr.CSV

Thanks for posting the code and data. You'll think I'm never satisfied but your code is just too long and complicated for me to follow. If you can, posting a minimal working example is what is needed.

For example, to import the data, shift the horizontal values in increments of 30, and plotting the result can be done in far fewer steps:

d = ConstantArray[0, 8];
Do[d[[i]] = Import["data" <> ToString[i] <> " " <> ToString[i] <> "0 Torr.CSV"];
  d[[i, All, 1]] = d[[i, All, 1]] + 30 (i - 1), {i, 1, 8}]
ListPlot[Flatten[d, 1], Joined -> True, PlotRange -> All]

Please find the attached notebook (the part of my code). Here my fitted function is complete profile and the fitted parameters (in the form of list) are- paramstobefitted, Areaparamstobefitted, BGparamstobefitted, etalonParamstobefitted . These are parameter lists in the form they appear in profile function. This code works well but taking lots of time. Can you please help??