I am currently working for the French company as a junior consultant. I started over a year ago here and successfully completed 2 programming projects. These projects went fairly good. It had it's ups and downs, but I was able to work it out.
Currently I have been put on a 3rd project in the same company. This is a project that was already going for a while and they needed more workpower so they (the manager) asked me if I could help. Before accepting it, I checked what had to be done and I saw that there were quite a few things I had no experience with. When I addressed this to the manager, he made sure I would get the necessary help from colleagues. And with that, I accepted the project.
Now, almost 3 months later, things have gone down hill very fast. The seniors on this project are working very hard to fix all problems while trying to implement new things that were on the schedule. I often get smaller tasks from them to speed things up, but (mostly because of my lack of experience for this project) I am unable to finish it in time and do a lot of things wrong what has to be fixed by the seniors who are already loaded with work. Last week something similar happened and because of that, 2 seniors had to work a whole Friday night to fix my mistakes. (Which they clearly weren't happy about...).
I am not glad with this neither. I feel useless or even more like a problem. I get stressed from workload I know I won't be able to do. I have even been sick for weeks because of all this stress I get. Compared to my previous projects (in the same company), I have no hope that I will finish this well.
I know a broad question is not really a thing here, but what can I do in this situation? I honestly already thought about asking the consultancy company to send me to another company with a project that I might handle better. I know this will put my in very bad daylight, but I seriously don't feel home at all in this project and know that even the others working on this project don't want me there anymore.
So maybe I can ask it this way: what can I do if I am put on a project that is totally not a job for me?
EDIT: thanks for the comments and replies everyone. To answer a few questions:
I had a performance review a while ago and everything seemed to be positive. They were clearly glad with my work, but this was before the 3rd project started so I don't think the manager knows about the current situation unless some seniors told it.
I can't upvote anyone (Stack claims I am not logged in?) But I will keep all your replies in mind. I will start studying documentation (if there is) and tell the manager about the situation of things continue like this.