Confusion reigned today in Rhodesia as both blacks and whites struggled to understand what their future holds now that the British settlement plan has been rejected and the government appears to be going it alone - once again.

To many Rhodesians the situation appears, as one prominent Salisbury businessman described it, both ironic and tragic.

The White-minority government yesterday rejected the British plan to settle Rhodesia's 11-year-old constitutional crisis, thus throwing out the opportunity to get much-needed Western financial support and a guaranteed end to the four-year-old guerrilla war, which went along with the package settlement deal.

Yet the government of Prime Minister Ian Smith also announced that it still intends to move toward black majority rule within two years through negotiations with moderate Africans, and promised to eliminate all forms of racial discrimination.

The two stumbling blocks that will create trouble for the new Rhodesia effort are:

The whites will negotiate only on the basis of the original proposals that called for near parity in the sharing of power, which the blacks have rejected. The whites, however, do not accept British involvement in a transition government, which the blacks accepted.

Smith will negotiate now with moderate Africans, not the nationalist leaders involved who have international recognition as the leaders of Rhodesia's 6 million black population. The likelihood that the Western powers will reject the new Rhodesian action as inadequate has led to bewilderment and despair at home.

In a series of interviews today, many Rhodesians, both black and white, said their reaction to the government's announcement made little difference. As a middle-age white store salesman said: "It's the outside world that now decides what is acceptable and what isn't. What I want or what my African domestic wants doesn't seem to matter."

An editorial in today's Rhodesia Herald said: "It is a question therefore of how the world reacts to the introduction of these measures - not so much now, but in the fullness of time and if and when they have proved to offer the best and safest solution.

"And in this context, much will depend upon America, to which Mr. Smith so clearly pleaded last night, and South Africa. But it looks like a long haul, fraught with danger."

Foreign Minister P. K. Van Der Byl said the government's decision again to move alone should not upset the rest of the world:

"We have made an irrevocable commitment to majority rule within two years and we are also irrevocably committed to elimination of the remaining forms of discrimination.

"If discrimination is done away with and majority rule comes along and we make an agreement on that basis within the terms of the Kissinger plan with the representatives of the 6 million Africans in Rhodesia, what else could anybody possibly want?"

But a prominent white businessman was pessimistic: "Apparently it's too late for us to have a real say in a settlement. The black governments and the nationalists now want more than parity.

"The government has waited so long to make this move that they [the blacks] obviously don't want us, and they're the ones with international support, so the world won't recognize what we do even if it's what they've asked us to do for so long. It's ironic and it's tragic."