I'd say something like this:
Hey, mate, I can't do the project alone. I'll need your help.
It's better to tell him whose help you will need, if you want him to help you.
If you want to use the longer version, you'll need to correct it. keep expectations from me means to avoid telling you about expectations. That isn't what you're trying to say.
Hey, mate, please don't have [or get] the expectation of me that I can do the project on my own. I will need your help.
Note that we say on my own, not by my own. Also, this is pretty wordy. If you want to convey the same thing in a bit simpler way, you could say this:
Hey, mate, please don't expect me to be able to do the project on my own. I'll need your help.
Another variation, a bit less formal:
Hey, mate, please don't get the idea that I can do the project on my own. I'll need your help.