Yesterday I was doing a solo top against a Nidalee and Singed and it was difficult to me, although I died "only" once and got their turret first, in my opinion I lost the lane because I could only archieve some push because they were going to other lanes often and thanks to our jungler I was able to kill Singed(Nidalee ran as fast as she can away).

My situation was like this, they pushed me to my turret and Nidalee started to spam her Javelin on me while Singed keeps the push and defends her. Any attempt of attack would screw me because Singed would fling and slow me then I would be focused, IF I could deal any damage Nidalee would be able to heal anyway. So I focused my efforts on defense by leveling up Spikes to be able to kill the minions fast and so less creep steal by the turret and less time to Nidalee range attack my turret. Sadly, at some point I failed to dodge her Javelin three times in a row and became only half healthed, Singed saw the chance and dived using his ultimate, I wasn't with my boots AND oom so I couldn't ran away and died.

There were any thing I could done to archieve better score?

TL;DR: How I solo against Ranged/Healer and Tank like Singed or Blitz?

All you can really do in those lanes are farming as much as possible, avoid dying, keep track on your lane opponents and ward river. At least that's as far as I know, you can't really hope to get any kills and shouldn't really go for them unless you get help from the jungler, which you did.
So no I don't think you could've done that much different, other then not get hit at all by nidalee

magic resist.

Sit by turret and farm. Then farm some more. In those situations, you might want to pack Teleport so you can buy quick and get back before you lose too much CS to the tower. Keep river warded at all times so your other lanes can keep tabs on when they leave to potentially gank.

@Skjuludde
I know I should have dodged her javelins but Cho is of slow and big, so it was difficult to me LH minions and dodge at the same time.

@REVERSEPOLAR
How would I get MR? I was zoning at my turret, if I went back to the shop to buy Null-Magic Mantle they would take at lease half of my turrets life.

As Skju said, I guess the only solution for such a situation is ask the jungler to pay more visits. =/

Edit:
@Hobo
Yes, thats what I did. Leveled up spikes for easier LH and tried to finish the minions before the turret does so. I usually take Exhaust and Flash with me, flash for obvious reasons and exhaust to make it easier to our carry catch their carry. I like teleport, I take it when I solo top with other champions but as Cho, who usually don't have the need to blue pill, I'm used to take exhaust.
Anyway, next game as Cho I'll take the tele.