Bad debt karma: let it go or pursue? Pursue how?

Friend who makes a lot of money & spends freely asked me for a loan. I put it together. Substantial. Called him a bit less than a year later when it was about to be due. He was all smarmy about how hard he was trying but had obviously forgotten about it. He is earning lots. I can’t stand to approach him. I don’t call him. Icy silence is the best I can do till I get better advice (or the money). Stuck.
Need perspective.