Emphasis structure: It should be ...

[Tedwonny]

Can I say

It should be I who should thank you?

It sounds a bit clumsy, but I want to stress 'I want to thank you.'

THANKS

[Chicken Sandwich]

***** NOT A TEACHER *****

It doesn't sound very natural to me. There is a more concise way to express this idea:

- Thank you.
- No, I should be thanking you.

Or a bit longer:

- Thank you.
- No, I am the one who should be thanking you.

[Barb_D]

Don't worry about structure. Worry about sincerity.

I hope you know how much I appreciate what you've done.
I truly appreciate all you did to help me.
Etc.

[Tedwonny]

Thanks a lot to you all

How , then, can I begin with the emphatic structure

It is I ...... ?

Of course sincerity comes before everything, but I'm just learning the structure here =)

[Chicken Sandwich]

***** NOT A TEACHER *****

It is I ...... ?

Yes, this is possible. You could say 'It is I who should thank you'.