Knowing when to walk away?

I have been doing my PhD full time since about February last year. I think everything that could go wrong has pretty much gone wrong. The funding that was supposedly there, wasn't really and I have spent 6 months writing proposal after proposal trying to get it back, the project partners don't pull their weight which is stressful as it involves animals, there is a lot of work conflict due to the fore-mentioned partners not pulling their weight, plus one of my major experiments is kaput and unfortunately that was my fault.
So now I am second guessing myself about what I am doing here. Am I cut out for this? Is the world trying to tell me something? Or is it worth it just to keep going on? It is not like any other job where you can find somewhere else to go. If I leave I really can't go back to a PhD so I am not sure I want to totally close that door IYKWIM.
Can anyone give me some good advice?

I'm a believer in signs from the universe and I can understand from your problems why it would feel like the universe is against this but I'm wondering if it is more the universe testing how much you want this by putting roadblocks in your way, seeing how resourceful you are?? how you are able to overcome obstacles??

This is something you are obviously passionate about, try not to 2nd guess yourself. Can you start your experiment again? are you able to arrange different project partners?

Goodluck with it all.