Currently, your code doesn't do what you think it does. Be sure to read carefully the help on TDMS Write. As written, all your data is written to an Untitled channel and Channel-1. This is exactly as the help describes because of the array you pass in. You need to convert the array into a column of data and not a row. Again, I recommend reading the help file.
http://zone.ni.com/reference/en-XX/help/371361P-01/glang/tdms_file_write/
Second, you can view the data easily using the TDMS File Viewer.vi function in Labview. This can help you debug issues with your TDMS file (you'd see all the issues with your data format).
Third, I would recommend not using a TDMS file because they are so hard to handle and have lots of gotchas. I would recommend a human readable file such as a CSV. If this is long term, low repetition rate logging data, also consider a database.
However, if you must use a TDMS file, you have a couple options for find the data associated with timestamp. One way is just read in all the data and then do a search for the time stamp. Note that a time constant can actually be a double value (timestamp to double conversion) so all your data can be same value. Then just load in the full 2D array, pull out the data column for the time and find index of the closest value to the one you want. In one application I had, since the TDMS files were GBs, I did a binary search in the file for the time. So options abound.
