Yet that's no reason to let jealousy cloud your plan and you do need one-please say you have one-even if it's just keep writing. Maybe that's the best plan there is, to keep writing and block out all the other stuff. Don't worry about what someone else is doing, worry about you. You have no idea what it took for that person to succeed, maybe they've been writing for ten more years than you, maybe they wrote another genre and have fans from that, maybe after toiling for more years than you they just flat deserve it. Could you're writing never take off, yes and the question will be will you have regretted the time and effort you put into it? If the answer is yes then you aren't doing it for the right reason.
Personally, I think jealousy-a little bit-can be a good thing. It can kind of prod you to look at what you're doing with new eyes, are you doing the absolute best, is there something you could be doing but aren't, maybe you can take a look at the other person and get some pointers. I grew up with three brothers and I have always been a competitor, it wasn't reward based praise I needed it was, ha! I beat your ass. (the therapist said it wasn't a big deal, I had bigger issues to deal with)
As I mentioned in a previous post what stuck a prod in my ass was seeing someone do well and all I could think was, no fucking way because I could do sooo much better than that.
We all have our buttons that get pushed. I think the most important thing is what do we do when they get pushed?