dizzyness and time between sets

When I do heavy (for me about 60 pounds on belt) dips, I get very dizzy and disoriented. I know this is probably not normal, but is it a sign that should be heeded or just something to work through.

Also, I would like opinions on time between sets. For information purposes, I am tall and long limbed. Whether I am going heavy or light I find if I only rest a minute or even two minutes, I rarely can perform the prescribed reps or weight. If I wait longer, of course, I can finish the routine. My question is, since my numbers continue to go up is that what is important or should I try to focus on “intensity”. My experience with intensity so far equals quick failure. Thanks.