Does this help? (see example)
I understood that you wanted everything in 1 column.
Tip: avoid using unnecessary message boxes,most users are annoyed by them and have to perform an additional action,namely pressing a button.
Do not close the userform unnecessarily,maybe the users want to fill in more data.
The modification was good.
However, if the user enters a number in the textbox for letters it is also accepted, for this reason when placing that message it was to explain that he could enter only Letters or only Numbers by obligation
I ajusted the example, as you wil see, It is impossible to enter letters in the Numeric fields,and it is impossible to enter Numbers in the non numeric fields. Certainely no need for these annoying messageboxes.
You seem to have very little faith in your employees.