Yes anything can brake if you tighten it to much.
rubber supply hose needs replaced.
The service engine light came on because the OBD (on board diagnostics) system detects something is wrong. The OBD system has set codes. You need to have the codes read to determine what to do next. Many auto parts stores will read the codes from your vehicle for zip if you purchase the parts necessary to make repairs from them. It may be as simple as a tune up.