Do more short high effort intervals. Find a track to run at if you can and alternate easy/hard laps. The visual cues of a track will really help you feel confident pushing hard because it’s easy to see how much distance remains.
Also, check out your local running clubs on Strava. I know social running isn’t for everyone, but it’s a really good way to push your speed up. Every club I’ve run with has been psyched to get a new person.
