Wissa scored twice in DR Congo's 3-1 victory over Uzbekistan to help them qualify for the knockout rounds for the first time in their history. They face England in the last 32 in Atlanta on Wednesday.
"That's why I'm even prouder than everyone else in this room," Wissa told AFP. "I didn't show my best face at Newcastle, but I knew that my time would come. This time is now. I just show to everyone now I'm in a good place.
"I'm good physically, I'm good mentally. So that's why I'm proud today to show that I'm a good player. I'm happy with what we accomplished. Now there's another path waiting for us.
"A big beast is waiting for us. We need to enjoy this kind of game. We deserve to play against England, one of the best in the world. I'm looking forward to what's coming next."
The 29-year-old reflected on what the achievement means for a country dealing with ongoing conflict.
"We are a proud country. We are proud people. We love our country. We love our national team. We love what we represent!" Wissa said. "I think tonight we just showed what it means for us — just to fight no matter what. It's not easy in our country. There's a war in East Congo. Every day, every time we wear this shirt, we think about them.
"That's why tonight, what we show is just to say that guys, no matter what, we need to keep going. Because we want peace and for them, I just say 'thank you'. Thank you because we came from far. We came from nothing to be here. Now we write our story with a black pen and we need to be proud."
Wissa managed just three goals in his first season at Newcastle United after joining the Magpies for £55m from Brentford. Three goals in as many World Cup group games represent a significant statement of his quality and fitness at a time when the club will hope he carries that form into the new campaign.