I'm sorry for you, vix. I know how painful depression can be. Only those who have been there know the difference between being sad and being clinically depressed.
Studies show that winter tends to bring people down. There is a doctor that I follow in youtube (search for doctor of mind) that increses the antidepressant dose of his patients during the winter.
You should not be satisfied with the current states of affair. I read a reliable source saying that the pdocs today should pursuit the complete remession of depression.
I lived in England, EUA (a bit), and Brazil, and my impression is that the doctors in England (and perhaps in europe) tend to be more conservative, and the GPs are don't have much experience with combination of medication, or with "stronger" antidepressants.
SSRIs are the first line nowadays for depression (fluoxetine, paroxetine, citalopram, escitalopram, sertraline) because: (1) they are very safe (you can take fluoxetine while pregnant, for example); and (2) because they work pretty well for about 1/3 of people. They have minor differences. For example, fluoxetine tends to be more activating (which did not happen with me), paroxetine tends to be the best for high anxiety, citalopram tends to give less side effects.
However, SSRIs are not the only option, and one medication is often not enough, and the dose has to be adjusted in several cases. I read I study comparing the strategy of using fixed 20 mg of fluoxetine vs using 20, 40, or 60 mg of fluoxetine depending on the patient response. More patients under the second strategy achieved remission.
Another example. I'm taking 60 mg of fluoxetine, and could get rid of the intrustive thoughts and deep sadness. However, my motivation was still low, I had fatigue and sleepness during the day. The strategy that my pdoc used was to add Bupropion to my regiment, which is a very activating antidepressive, act on different parts of the brain than SSRIs, and is know for being good for depression associated with fatigue/sleepness. Guess what? I'm motivated again and have much more energy.
There are several other options. For example, venlafaxine is a strong antidepressant, but still in the category of reuptake inhibitor (SNRI), which means that they it is still very safe. The doctors don't start with venlafaxine because its side effects and withdraw might be more intense, and because a simple SSRI might work. So why try venlafaxine first? But IF SSRI is not enought, a pdoc can safely prescrive venlafaxine for you.
What I said above are the only options? No, there are many more. For example, an antidepressant of TCA category can work for you. However, they are less safe than SSRI. And again, this is the reason the doctors don't start with a TCA antidepressant.
My point is: don't be satisfied with your current condition. Tell this to your GP. If she/he is not willing to try other options, ask for a psychiatrist.
Best,
Danilo