Ah, if the warrant shows that California will not extradite, that explains why the Texas cop did not take you into custody on it.
A warrant of arrest can be withdrawn by the issuing authority (in California it is "recalled", which means that the warrant is no longer valid and you cannot be arrested on it. The only way a warrant for your arrest for failing to appear to serve a jail sentence
will be recalled is if you surrender yourself voluntarily before the warrant can be served.
Barring very unusual circumstances, you will almost certainly be required to do the full sentence you left behind here in California. Had you led an exemplary life in the meanwhile, the court
might be inclined to give you a break, but the fact that you went to jail in Texas (even if only for a minor offense) makes that very unlikely.
You could get more time, up to the maximum possible sentence for the sentencing crime, depending on what that crime was, why you left, what other probationary terms you did not fulfill and what else you have done in the meanwhile.
California authorities will probably not discuss this with you on the phone. Your best bet would be to hire a local California lawyer for the limited purpose (at least to begin with) of determining your warrant status and what might likely happen if you came back. You can contact the county bar association of the county in which your conviction occurred regarding a referral to an attorney on their lawyer referral service panel. You can probably do a consultation over the phone and the cost will be minimal. Then if you decide to hire him to help you, you make arrangemends directly with the attorney for payment.