Formula Troubles, Stressed Momma!

My LO is a month old. We started on the regular Enfamil (yellow label). LO was spitting up PROFUSELY! So we switched to Gentlease. While the spitting up is FAR better, we are now dealing with constipation. Plus what I’ve thought to be baby acne the whole time since LO was born, more keep popping up. Is it possible LO has a sensitivity to cows milk? Weight gain has been good since coming home, even with all the spitting up. As stated above the “baby acne” has been popping up since birth. But now we helped one “problem” and created another with the constipation. Has anybody else gone through something similar? What helped?