How do you handle awkward moments where something is going well for you and badly for someone else so you can’t commiserate like they’re hoping?

I remember what it was like to not, though. I meet them there and try to give them hope it gets better based on where I’m at now.

If empathy and support/encouragement isn't enough, that is something they need to work on themselves. I absolutely understand the need to just vent and let yourself feel what you feel, but I'm not going to let them make me feel guilty about my life going better than theirs, or give them a pity party if that's what they're really fishing for. Pity isn't empowering.

I usually try to focus on the other person when they're venting vs trying to relate it to my life anyway, which helps avoid that. I dunno if you can really avoid tension or awkwardness if their behaviour is the problem. I would feel inclined to change the subject or call them out on their behaviour if it seemed reasonable to do so.

I don't think you need to downplay the good in your life. When they ask about how things are going just be honest. You don't have to say it in a way that rubs it in their face, just tell them what's good and what is really going on in your life. Friends should be able to be there during the hard times and good times. They should be cheering on your successes not getting upset about it. If they do get upset then that's something they have to learn to deal with because that's not healthy.

Both situations are interchangeable really... i cannot give any advice because I find myself in similar troubling moments..that I can't say I'm handling with much grace...
What i say to myself is that if i were confident enough and stable enough in my goodness, I could go down for a bit to be with them. But since I'm struggling balancing myself and keeping me up, I can't afford to do that. Soon I'm dragged down for longer.
It is what it is, and it's very dynamic, relationships..be compassionate and give them time. Nothing lasts forever anyways, either the relationship will change or will drift apart..

Do they want to draw you down to their level?

There is. Find better friends.

One thing is to be empathetic towards less fortunate and the other is downplaying your life achievements because they still don't have theirs.

The way I see it there are four options of dealing with those kinds of situations:
* Calling them out or just have a real talk with them about it. Although that's something not everyone can deal with, that might end bad and they may simply be unable to realize the issue with what they are doing.
* Ending the friendship for the not-so-friendlike behaviour of wanting ill upon those who are your friends and who care about you. Obviously that isn't ideal and their behaviour may very well be unintentional without them understanding the effect of their actions on others trying to be there for them.
* Ignore it and just keep being honest about your life, meaning saying you like your job if it fits the conversation instead of sidestepping it, which will probably frustrate them.
* Or do as you already are doing, downplaying it and just trying to keep supporting without being dragged down to their state.

Simply put, as far as I can see there are no good options, just weighing what is the least bad in your mind.

I understand that from their point of view hearing others having a whale of a time while they are in a bad place may make their struggles feel even worse, and that there is some comfort in not feeling like they are the only ones who have a shit time... but there is a difference between struggling to hear about other's joys of the world and maybe respectfully requesting to not have to hear it, as opposed to actively wanting friends to have a bad time.