1997 Honda Accord engine running hot

I'm problems with my Honda running hot. At times it's good. Other times not. I never let it get 'HOT', I am a senior lady and take care of my car as best as I can. I've had a new sensor put on for the cooling fans. Hoses are all fine. Coolant is fine and doesn't lose any. I recently had to have an oil pump o-ring replaced, so I had the timing belt and water pump replaced. After that repair, my engine light came on and my speedometer quit. A speed sensor was installed and all that was fixed. But then today. The heat guage ran over halfway. Which usually stays between cool and half. After it cooled off. I ran it again. The same mileage, and it didn't run hot at all. But i'm on the road a lot and need to get this resolved. It's been a really great car. The oil pump o-ring was the first real repair i've ever had to have done, other than maintenance.
thanks ever so much! Please help!
Shirley Felts
thanks for any help you can give me.