Take equation 1, you are mixing current and voltage as terms and adding them together, eg.
-3 + I1, you added a V to a current :
You cant do a V loop on all outside branches because one branch is a current source and you
cannot determine directly what its V to gnd is. So correct dual symbol I1 problem, then do
a V loop right hand window. Or maybe problem is legit with I1 labling. So do V loop right hand
window, and use the current node summation you did for currents in/out of node formed by
R1, R2, R3.
Regards, Dana.