(Disclaimer : I am assuming you have T3c because you mention this in earlier posts.)
It's really good that you have got an appointment to see a diabetic specialist. To be honest, based on my experience, many/most GPs admit that they are moderately clueless about T1, and T3c can be more complicated than T1. (Basically, your pancreas does a lot more than producing insulin, including digestive enzymes and
glucagon.
https://www.medicalnewstoday.com/articles/316427 )
I used lantus happily for a decade, but then found that it became unreliable for me - not lasting the full 24 hours plus I had a couple of lantus lows. New Zealand is very limited in the basal insulins it supplies, so I didn't have the option to change. I found that splitting the dose plus waiting 15 minutes after taking the night time dose before sleeping, both gave me relief from fearing lantus lows and better 24 hour control. My team then swapped me to a pump because of continued issues with hypos (not caused by the lantus) and that has massively reduced hypos, and improved my diabetic control and my life. I would hope that your main issues at the moment are caused by lack of information about T3c, but if hypos continue to be a problem I would recommend asking your team about a pump.
Good luck with the appointment.