Selling winner stocks during year of realized net loss: a good idea?

Yes. Capturing gains to offset the losses makes sense, for you.

But. Keep in mind, long term capital gains can be taxed at 0%. But the losses can go against ordinary income, so even at 10%, you might benefit. If the gains were short term, and you want to sell anyway, no problem. But churning the stares just resets the clock, so I’d analyze the situation carefully.

I think that it's a good idea to harvest gains when you have losses in order to reduce current or future taxation. And even if you didn't have those losses, booking the gains in low income years has merit as well. Because my income is highly variable, I incrementally cashed out a chunk of my IRA in low income years because at some point the RMD withdrawals will become mandatory (I'm much older than you and closer to that).

There are some potential gotchas in your strategy. If your losses were in the same stocks that you have open positions in with gains, you would have to make sure that you did not sell the gainers and buy them back within 30 days of the realized loss because that would trigger a wash sale violation, forcing you to defer the losses.

Another consideration is that you are limited to a $3k capital loss per year so if your 'large amount of losses' exceeds that, you would not get the benefit of them this year. In fact, they would be of little to no benefit because you indicated that you have a low income and the $3k deduction would be wasted. So it would make perfect sense to use up as much of the realized losses as possible.

The only other drawback that I can think of is that if you sell your short term winners and buy them back, you lose the 'time in' towards the one year long term gain status. I don't see this as a big deal if the holding period has been a few months and the tax savings (assuming a higher future tax bracket) is significant. If only a few months away from LTCG status then maybe not.