I believe I can help you with your concern
I am so sorry that your Venlafaxine stopped working for you after 10 months. You stated that your medical doctor increased your dosage, what is the increased dosage currently?
So because you used 150mg of the Venlafaxine for 10 months, I would assume that you should start to notice the effectiveness of the increased dosage in around 2-3 weeks and then at around 5-8 weeks, you should get the maximum effectiveness of the increased dosage. But this really depends on what your increased dosage is currently at and how your body metabolizes the medication.
I was thinking your increased dosage would be at 225mg since 75mg is a usual increase that I have seen. Typically you want to find the lowest effective dosage for your symptoms because obviously at a higher dosage you are more at risk for side effects. If you are feeling no side effects that are troublesome and if the 225mg is working for you, then I think you can stay at the 225mg dosage.
Yes in my experience the 225mg dosage is very effective and usually it will help you considerably, but the medication only lessens the symptoms and does not cure you completely. Only therapy can cure you, so you should see a therapist regularly while taking the medication to get the maximum benefits.