Americans who have benefited from the Affordable Care Act are feeling some relief at the failure of Republican efforts to repeal it, but they face new anxieties with President Donald Trump tweeting that “ObamaCare will explode.” Premiums have risen and major insurers have backed out of the state markets where people can buy insurance online under Obama’s signature health care law. But people who say it saved their lives or helped them start a business want lawmakers to fix these problems, not encourage them. “It does need its fixes, I totally see that,” said Inge Hafkemeyer, 57, who credits the law’s subsidies for containing her costs as her home-based event-planning business took off in Mission, Kansas, a Kansas City suburb. “But if your roof leaks, you don’t burn down the house to fix it.” Clare Schexnyder, 49, is convinced she’s alive today because of it. As a small …