I'm not a doctor, but I have researched elbow injuries a bit due to my son's issues last year. The symptoms you list do sound consistent with a UCL injury. Get to that doctor's appointment. Try to find the best, closest sports injury physician working with elbow issues that you can. The physician will do a physical exam asking you to press against his hand in different positions, and move your arm in various ways to look for obvious tears. Ask for an MRI with contrast, as that will be the clearest view. And, even if they find a tear, it might not be the type of tear that requires surgery - might just need time and physical therapy.
Wishing you the best!