You could also try starting from first finger on fifth fret, so placing fingers on frets 5, 6, 7, 8.

Try that for a few days, then try starting on fourth fret for a few days, then third, second, and finally first, spending a few days starting from each.

If you reach a point where it becomes a struggle, simply spend a few more days starting from the last fret that felt more comfortable.

This would increase the amount of stretch over a period of a few weeks instead of attempting it from the start, which, in my opinion, can cause frustration instead of making playing the fun it should be.

Also, remember to relax and breathe at all times.