Your margin won’t change if both positions are the same size until you close the second trade. However, If your long position is bigger than your short, it will use the margin for your long.
Then you might as well close out the first 2 trades because they’re now obsolete, unless you plan on only closing the trade going against you and leaving the 2 open in the direction you expect price to go.
If you close the original profitable trade then you still have the original negative trade open that you need to deal with, plus you now have a new trade open which widens the gap between the two. You’re still hedging so that gap will remain the same no matter where price goes, unless you close one of them.
Hedging is stressful, it’s designed to protect your account from further loss, not to make money. There are hedging strategies that you can make money from, but you need to fully understand how they work because like any strategy it can burn you.
I would recommend doing a search on hedging here, there are many threads about them. I actually have some bookmarked, I’ll see if I can dig them up…
https://forums.babypips.com/t/can-you-hedge-in-forex-trading/997028/3?u=mattymoney
https://forums.babypips.com/t/trading-s-r-using-price-action/978106/9?u=mattymoney