800m/1600m Mid Distance Training?

I would suggest that you look mainly at your 400 and 800 times. They indicate to me that you have the speed but not the speed endurance.

Start to do 1 session a week of 200 meter repeats at your desired 800 meter time with 2 mins recovery. Lets say you want to run 2.05 then you run each 200 metres at around 2.05 pace. Start with 6 200's and work it up to 12 200's increasing it by one every training session. Focus on not stopping after each 200 but walking it out.

Also another training session is pretty much the same thing but 300's. always reassess these sessions after maybe 3-4 sessions to see if you are getting the desired results.

You may need to do some session for example like 400's with 1 min rest at 1.12ish pace start out with 10 sets increase by 1 until you get up to 16+ per session. Just to get the distance/speed endurance into your legs.

Anyways just providing suggestions ive run a 1.56 800 m 54 400 m

If you're a girl, you're certainly more speed oriented.