Re: use of correct tenses
You need to match the persent tense in this part:
I have learned that my body frequently gives (not gave) me ..
Or you could have said:
I had learned that my body frequently gave me ...
(The first means that up till now you have learned this; the second means that up to some point in the past you had learned this)
Continue that, but use the present tense for all verbs (as you did correctly, all but once):
I have learned ... my body gives ... has been going on ... has already told me
or use the past tense for the alternate meaning (set in the past).
I had learned ... my body gave ... had been going on ... had already told me
(and confirming is the spelling you're looking for on that word.)
Re: use of correct tenses
'I learned that my body frequently gave me clues as to what
was going on - even before I confirmed what it had already told me.'