Fantastic that you have an appointment with your GP. Never, ever feel that you are wasting their time. Be totally honest, they want to help. I suffered severe depression 6 years ago, the GP urged me never to wait to see them again. Had suicidal thoughts and wasn't functioning at all. Have since come off meds - with the right support you can more than get through this.
Less said about your counsellor, the better.............. Though, if you get someone good, it makes a huge difference. Ask at your GP appointment. Not sure where you are based, but if in South London, I have a great contact.
Depression is a lonely place. I used to think that was a cliche (too many movies?), but hit me that it wasn't. Just know that others are waiting to cheer you over the finish line. Us on here included.
Look after yourself - and please take the insulin. Every injection and blood test is an achievement.
Karen