I accidently took 100mg of tramadol norman as apose to 25mg in 1 dose 2 hours ago & now feeling dizzy & sleepy. Should I be concerned or sleep it off?

See below. If that is all you took and you have no other issues or took no other medications you should be fine to sleep it off. If concerned have someone watch over you for the next 4-6 hours. If you are really concerned, go to er or call 911.
You're fine. 100 mg of tramadol is the higher but typical dose of that drug. If you are not used to it, it may cause you to feel funny for a while. Relax and it will get better.
Sleep it off. That would not be unusual side effects at that dose. It should be ok to sleep as long as you were not mixing it with other medications. In general if you have this kind of question asking poison control can be a great resource. They have immediate and reliable information about drug overdose questions.