'I thought I would be a doctor' This is a sentence expressing a past plan, or technically a future-in-past statement. Can I say 'I wanted I would be a doctor' while I would be a doctor is the object of want? Is it grammatically or idiomatically correct?
I wanted I would be a doctor
is not grammatical. Want does not take finite clauses as complements with any time reference, only marked infinitivals:
I want (that) ∗I will become a doctor or
I wanted (that) ∗I would become a doctor.
I want okto become a doctor or
I wanted okto become a doctor.
The I wanted I would junction doesn't make sense. You need to put something in between those two in order for the sentence to flow smoothly. The best way is to make the sentence conditional:
If I wanted to, I would be a doctor.
This is a shortened version of the longer sentence
If I wanted to be a doctor, I would be a doctor.
You can also change the tense (completely optional):
Had I wanted to, I would have been a doctor.