I think it depends on how important the $50k is to you.
One option, if that’s literally all the money you have on the planet, and you raise enough outside capital … say > $1m … is just to get paid back. All, or at least some. As long as it’s < 5% of the round, the investors may be OK with this if it’s your entire life savings. They key is to be up front here. Don’t surprise investors here with this idea later. They may freak out, and see you as not committed.
Another option, if you have significant savings, is to convert into the first preferred / investor round via a note, discounted or otherwise. That’s OK. If you have the capital to invest.
A common middle ground with multiple co-founders is to convert instead at a lower price, or the common price. If you took all the financial risk early, paying the preferred price later doesn’t necessarily make sense. Maybe, you should get more common for it. The investors won’t care that much if their pre-money doesn’t change.