I am just forty three and keep losing my train of thought, could thus be an early onset of axhiemer?

Unlikely: While there is an early onset form of Alzheimer's, it is rare, and extremely unlikely at your age. There a many other causes for your symptoms - poor sleep hygiene, depression, anxiety, lack of exercise, uncontrolled diabetes, etc.. Focus on getting adequate amount of high quality sleep, increase exercise, practice relaxation techniques, and do brain twisters / memory exercises. Take Care!