The nationwide tax fever that led to last year's taxpayers' revolt and Proposition 13 largely has subsided, and the patient is back to normal, according to a new poll by the Roper Organization.

The survey, involving 1,502 Americans from all income groups and regions of the country, shows they are significantly less angry about the taxes they paid this year and express less discontent with the fairness of the system.

The poll also shows Americans strongly oppose a European-style valued-added tax, such as the one being considered by the chairmen of the two congressional tax-writing committees.

A VAT is a form of national sales tax imposed at each stage of the manufacturing process and ultimatley passed on to consumers at the end. It is used widely in Europe, but never has been tried by the federal government here.

The study showed 62 percent of Americans oppose a VAT, even if it is used to offset existing Social Security taxes, as sponsors suggest. Some 48 percent of taxpayers said they'd rather see Social Security taxes rise.

In addition, the survey showed 61 percent of taxpayers in favor of indexing the tax system -- that is, providing for automatic reductions to offset the impact of inflation in pushing taxpayers into higher brackets.

The 227-page study was the third in a series of annual polls on tax issues sponsored by H & R Block, a tax-preparation firm. The poll, which Roper conducts independently, has become the most comprehensive on tax matters.

This year's sampling also shows that the public believes there is widespread cheating on federal income tax returns, either by overdeducting or shading income. People also believe about 7 percent of eligibles don't file returns at all.

The findings that last year's tax revolt has waned was described by Roper as a major turning point. The study labeled the development "an important change of attitude that will have far-reaching consequences . . ."

At the same time, however, the poll shows continued widespread support for a constitutional amendment limiting government spending, though not necessarily requiring a fully balanced budget.

And the survey shows the public also would be willing to approve constitutional amendments mandating equal rights for women, prohibiting forced busing, permitting prayers in public schools and controlling hand gun sales.

The strength of public opposition to a value-added tax was expected to mark a setback for backers of the measure. Supporters of a VAT have touted it as the only practical substitute for rising Social Security tax burdens.

Rep. Al Ullman (D-Ore.) and Sen. Russell B. Long (D-La.), chairmen of the two congressional tax-writing committees, already have endorsed the measure and have pledged to hold hearings on the plan sometime this year.

Along with the findings on tax fever and the value-added tax, the poll yesterday probed public sentiment on a variety of other tax and spending issues. Some of the results:

As expected, the public believes the controlling inflation is the number one issue in the nation today, with increasing energy supplies second. Reducing Social Security taxes is last on a list of 15 items.

The public generally approves President Carter's proposal for a windfall profits tax on oil, but wants the bulk of the money channeled into energy research and development -- preferably through a plowback exemption.

About 55 percent of Americans want to keep the current system of financing medical costs rather than adopting a national health insurance plan such as the one advocated by Sen. Edward M. Kennedy (D-Mass.).

An overwhelming 72 percent of Americans believes taxpayers ought to pay taxes only on the wages they earn, and not on any fringe benefits they receive, as the Internal Revenue Service wants.

Those favoring a national health insurance plan were divided almost evenly between supporters of a comprehensive bill covering all costs and a scaled-back version limited to "catastrophic" illnesses.