J.B.
3.5 is the pinnacle of awful, really. When my oldest was 3, I was so convinced that I was raising a sociopath and future serial killer that we went to counseling. She assured me that really, he was just 3, and totally normal.
My sanity saver was the book "Raising Your Spirited Child." It was such a relief for me to know that it wasn't me, he really was "more" than other kids - more stubborn, more intense, more needy, more everything. It not only validated my perceptions, but gave me perspective and coping strategies that were enormously helpful.
I can tell you that he became a new kid when he was 4 and has become easier and easier with every passing year, but I think a huge part of that was that the book made me understand his temperament better so that I was able to better anticipate his quirky needs and respect his limits. He's 15 now and still is my biggest parenting challenge, but he's a delightful person whose company I really enjoy and is a person who I would like even if he weren't my son.
Hang in there, it's 99% his age and it does get better.