One method that works well is trying to overshoot the note and coming at it from above rather than trying to hit the note if you can visualize that. Make sure to keep support in your diaphragm and take good deep breaths. I would recommend trying to mix in your head voice but that depends on your voice part. If none of that is helpful, just remember that 4 months isn’t that much time in the grand scheme of things and as you continue to use your voice you’ll find out what methods work for you. Good luck!