This is great for your first ever entry to Finish the Story. Welcome :)
Your ending flowed really well from the first half. I liked your character, Isabella, you gave the protagonist more depth with this dynamic.
As the first half was in first person you maintain that really well, except for this one pesky paragraph:

All he wanted was to retrieve that mail, noticing my enormous interest and without asking any questions, he took his laptop and assembled it with my pieces and told me to use it as long as I wanted.

You change from 'I' and 'My' to 'He', which is an easy mistake to make. Try to look out for this sort of thing when you read through and make edits.