B.Arch

Answer is both yes and no
If you are considering a change in profession from engineer to designer it is worth considering. Unlike engineering, designing field is different. You need to develop lateral thinking, there is no right answer in designing, it is always about finding different ways of approaching a question rather than a straight path. No complex calculations (if you are designing luminaries, there are few, but I can't call them complex). Here are the things you will learn if you choose interior designing. You will enjoy the course if you are really passionate about it. You will learn there are many ways to approach a problem and there are many answers to the same question
You learn to appreciate the designs. You learn the detailing. You will miss the routine that is found in engineering, since every project is different and every project is a new challenge. You will learn designers are late bloomers. Designing is fun but you will find that will pay you less. Your experience in civil engineering will not help you a bit in interior designing. Opportunities as a designer are less compared to engineer. My advice would be it is your life so your call. None can help you there. You can choose this field or you can be an engineer. Good luck.