They don’t know if it’s type 1, 2 or 1.5 which I have never heard of.
Are they doing any blood test to determine the type? Do you have any idea what your hba1c was/is? Are you underweight now?
I wouldn't make any assumptions about diabetes type until you've had the tests, to be honest, as the very fact that they mentioned the other types to you means that they think they are a possibility.
Basically, if you are T2 your insulin doesn't work properly for you, you are insulin resistant. Your body produces more and more insulin in an eventually vain attempt to control your sugar levels. T2 is often (but not always) accompanied by weight gain because high levels of insulin plus high levels of sugar in the blood tend to lead to fat gain. If you are T2 then carbohydrates are your enemy and reducing them can often reduce your blood sugar levels and reduce or even eliminate your need for medication.
If you are T1 then an autoimmune condition kills off your insulin producing cells, generally fast for children and young people, potentially slower for older folk (also called LADA or T1.5 then). T1 is often accompanied by weight loss (though that can happen for T2s as well), so that may be why they are considering it in your case. If you are T1 then you will eventually need insulin, though many people can delay that need for a long time by reducing their carb intake, as if you eat less carbs you need less insulin.
But as
@JoKalsbeek said, if you decide to reduce the carbs in your diet (which should help whether T1 or T2) you need to watch out for those hypos.
Good luck. A diabetic diagnosis is initially very frightening, but even if (worst case) it is T1/T1.5/LADA it doesn't have to stop you enjoying your life. But it may take you a while to get used to it.