Can i still use the linear model if this happens?
Everything is telling you that this model does not fit the data well:
the t-test for the
xiestimate gives a p-value that is comfortably above 0.1
since there is only one variable, the omnibus F test gives the same p-value
compared the the intercept, the estimate for
xiis tiny. Even if this was "significant" I would put it to you that it is likely that this is meaningless in the context of your experiment/study.
$R^2$ is quite small: 0.18
It is not clear what you want to use this model for, but I would suggest that it is not very useful for anything. I assume you have plotted the data ? Unless there is a clear nonlinear association between the 2 variables, then you will likely need to include some other explanatory variables to obtain a useful model.