Hello,
Your night time dose of lantus does need to be increased (typically increase is by 1 - 2 units every 3 days) until your target fasting blood sugar the next day is reached. However, this should be done under supervision of a doctor or diabetes educator.
You need to find a new doctor who will help you adjust your insulin appropriately. You also need to read up on diabetes and it's management. Recommend the book "think like a pancreas' or "using insulin".
What is your a1c? target is < 7.0 or even better < 6.5. (people with excellent control may be able to achieve a1c in the 5s, without lows if they follow basal-bolus dosing approach combined with low carb eating).
A detailed answer is not possible on an internet chat board. Lantus is a terrific drug, and I am disappointed your primary care physician has not seen fit to provide you with more detailed guidance.
I urge you to find a diabetic clinic with a nurse-practicioner and a dietician who will work with you on a daily basis for a while, then a weekly basis to insure you know how and when to administer Lantus.