The other thing is, when you read accounts online from people who've had difficult side effects, remember that there are millions of people taking them — according to this news article, 8.3 million adults in England (I think there's about 42 million adults in England in total?) have had antidepressants in the last 12 months www.bbc.co.uk/news/health-62094744.amp — it only takes a tiny fraction of a tiny fraction of people to have an unusually bad reaction for there to be loads of reports, while you're less likely to hear from the people for whom they're okay. Millions of people take them in this country every day (I know the numbers above are just England, but I would guess the rest of the UK's numbers won't be that different), and people wouldn't take them (or doctors prescribe them) if they didn't feel that the benefits were likely to outweigh the side effects.
The people who get a couple of weeks of feeling as shitty as you do now who then find that the side effects mostly go away and the drugs start helping tend not to post as much about it as the people who get intolerable side effects; people who get bad side effects are more likely to need to reach out for help, and we tend to report bad experiences more readily than good ones.
This isn't at all intended to belittle what you're experiencing, just an attempt to reassure you.
If you're still having intolerable side effects after a few weeks, then you can try a different antidepressant — that's also a fairly normal thing to do, because different people find different drugs suit them better and sometimes the first one tried was the wrong guess.
I speak as someone for whom almost all antidepressants have side effects that mean I can't take them — I know I'm in a minority and that lots of people find them helpful. But you do sometimes have to wait a few weeks to find out if you'll be able to push through the initiation effects and come out the other side, or whether you'll need to try something else, whether that something else is a different drug or a different approach altogether.