Like other answers, you may be overdoing yourself.
When you lift weights, you're putting your body under serious amounts of stress to complete the rep. This will provide pain after excessive amounts of lifting. When you stretch, it provides relief to the muscles as they are undergoing something that isn't a tension, but sort of like a release if you like. It gives the muscles a break and stretches them with no risk to muscle injury.
Stretch before and after a workout, but if you're stretching to release pain then I advise you take a rest.
When you lift weights, you're putting your body under serious amounts of stress to complete the rep. This will provide pain after excessive amounts of lifting. When you stretch, it provides relief to the muscles as they are undergoing something that isn't a tension, but sort of like a release if you like. It gives the muscles a break and stretches them with no risk to muscle injury.
Stretch before and after a workout, but if you're stretching to release pain then I advise you take a rest.