People you perceive as “successful” may themselves be facing internal hardships. Placing self-worth in externally-controlled goals sets you up to feel bad about your place in life.
I used to beat myself up about my current progress and constantly comparing myself to others. Once I stopped doing that and instead focused on making small incremental goals, I started to feel much happier. It seems counterintuitive, but once I stopped focusing on “success”, I became much more successful in what I actually wanted to accomplish.