Hi Tracey, I had problems on Lantus, if you read my postings it'll explain. It may not be the problem, but prob worth looking into.
While on lantus I had no predictablility from day to day with my blood sugars and I felt deathly. I repeatedly reported the problems to my GP, hospital doctors and nurses, no one suggested that lantus may be causing the problems. I had lousy control and started to think there was something really wrong with me. I'd have days when it didn't seem to work at all, and days when I was severely hypo all day, and I wouldn't dare take my rapid acting insulin. It was scary, and very frustrating . I had been type-1 on insulin for 15 years before I went on Lantus- I had never experienced anything like this previously or since. I went on to Lantus on the advice of my hospital nurse, as she assured me it was superior to other insulins. I came off it bout 6 weeks ago, and changed to Porcine Isophane and life is far better. I now have good control and feel better generally. Every day, my blood sugar is predictable and I feel that I can trust the insulin I am taking is acting in the correct way. Other people report similar experiences and symptoms, suchas severe lethargy, feeling flu-like and generally unwell, muscle pains and tremor- these are some of the symptoms I experienced.
It's prob worth you doing a google search yourself, and seeing if the symptoms and problems other people experience are similar to your own. Glargine(lantus) is an Insulin Analogue and not actually insulin-it's a drug that lowers your blood sugar.
Of course, none of what I have said may have anything to do with why you're feeling unwell, but worth looking into.
Jus