For me, I take it easy. I believe if that person is meant for me, he will be. Otherwise, no amount of effort that I put in will make that person mine. People's heart changed. People changed every single ticking second. I adapt to changes fast and I hope so do you.
Chasing after a person and snooping around is just an act of insecure heart. You can put in effort to make a relationship work. But if it comes to a point that it's stressing you out, you need to take a chill pill and pause for a while.
If they are really meant for you, they'll come back. There's absolutely no doubt about that. Some people just need a space to realise our presence. No one in this world likes to be chase around. No one likes a stalker or their things to be looked through.
At any point of the relationship you have to look through your partners stuff, it's a sign to abort ship. Don't waste time on people that don't care about your heart. Both side needs to make an effort for the relationship and not only one sided effort.
One thing for sure is we are gifted with instinct. Make full use of it. Don't walk around in love with eyes wide shut.
May we find the true love that we seek. Have a wonderful weekend.