Hiya Change -
great to hear about the visit, despite you yourself feeling not that wonderful... that step is a practical move in real life that deserves applause. Often (in my case), feelings are 'lagging' a bit compared to the events that actually were brought about by yours truly. So it can take days before I say to myself: hey, Cuthbert, what you did was pretty good, wasn't it? I guess that it has something to do with the dreaded 'catastrophic thinking' inherent in OCD: I tend to first go through things that I potentially might have done wrongly (complete with possible consequences of those wrong actions, that did not happen in the first place!) - and only later my mind is free to see that it was, in fact, right what I did.
Now: the matter of paroxetine vs. sertraline. At a first glance, I could not find significant differences between the two, both serve the same goal, namely to increase the levels of freely available serotonin (a messenger molecule) in your brain. I will delve again into the matter shortly, when I'll have the time. Well, there have been stories about the initial effects of paroxetine in children - these suggested that they became more depressed after having taken their first doses, up to the point where they felt so bad that they thought about dying. But IMHO these were not that well substantiated, and referred only to single cases. Could be that your GP is a bit wary about prescribing paroxetine on these grounds, that is her good right. But on the other hand: had paroxetine really such grave initial effects, then it would never have been put on the market in the first place. I myself use it and never had bad effects.
Taken together, I guess sertraline is as good as any other SSRI type of medication, including paroxetine (SSRI: specific serotonin reuptake inhibitor). So if I were you, I would not worry overmuch about this issue.
And I am sorry for you that CBT comes with a long waiting list. Governments could do worse than eliminating these obstacles altogether. But they aren't generally known to be fair in distributing money, in a way so that human needs are met where it's really urgent.