1997 Honda Accord SE with cold start high idle and fluctuating idle

I've had my Honda since it was brand new in 97. I've done all the maintenance and repairs myself and just recently have come across this annoying problem. It started out as just a fluctuating idle and a check engine light for the IAC valve. I pulled the entire intake assembly off and cleaned everything including the IAC valve. Also adjusted the fast idle valve. Put everything back together, cleared the check engine, and the idle seemed to go back to normal for about a week. The check engine came back on for IAC valve along with the up and down idle. Purchased a new IACV and it cleared the check engine but did not solve the idle issue, but actually added the high idle at cold start. So I then cleaned the EGR assembly and exhaust ports with no success. Also put in new O-rings for the spark plugs because I had a leak into the 4th cylinder figuring that could been the issue with it missing. Still no success. Then I noticed that my upper radiator hose was collapsing which was a not issue before all this maintenance. I then flushed the system, replaced the cap, replaced the thermostat, made sure the reserve return hose was clear, bled the system and still no success. Now the new cap is leaking coolant all over the place after the car warms up and the idle issue still remains. Im at a loss and am wondering if this could be a head gasket problem. The car seems to still have great power and drives just fine. The idle issue is only apparent in park. There's no signs of coolant in the oil. No more check engine light. Ran the car as suggested to cycle the computer. Any suggestions. Please help.