When you convince yourself that going in a different direction doesn’t make sense because you’ve “put too much into this,” it’s hard to conceive of how different (and awesome) life could be if you made a radical change. Thinking you are indebted to your efforts of the past will only keep you stuck and unhappy, sinking more time and costs into the fallacy.
Don’t beat yourself up, and don’t live with regret for what you could have done differently. Mostly, don’t let your past spending hold your future happiness hostage.