Hmm.......well, yes. Fasting 'signalling' can fool the body into believing that starvation conditions prevail. The body's survival response to that signal is to conserve energy, and that must by definition include a reduced metabolic rate. That could also be an explanation for you feeling tired. It all fits in. And it's not so unusual either. I've had similar experiences from around day 12 into a fast, and it usually lasts for around a week before things get going again.
The only way to overcome it that I'm aware of is to ensure that you remain 'active'. If you don't know what that means, do a search on this forum:
I tried posting a link for a relevant thread, but the site wouldn't allow me - some silly message about adult content.
It should give you enough ideas to kickstart that metabolic rate again, but you should also pay some attn to what I said about the benefits of intermittent dry fasting within this thread. You will be amazed at the results if you can get past the psychological barrier that insists on continuous fluid intake.
Giving up now while your metabolism is in 'trickle' mode would be a bad idea. Any food you eat will be largely converted into fat rather than used for energy, and any benefits gained from your fast will quickly evaporate.
If you can hack it, you should bite the bullet and see this one thru. As the song has it, it can only get better.