"我是专业的。勤奋。投入。忠诚。同时也多愁善感。但这些年来我有了一些变化。由于工作强度大，我的心灵变得有些沉重。"

Simplified Meaning:

A person is describing their work ethic and how dedicated they are to their job. They work very hard, stay committed to their tasks, and remain loyal to their employer. They also mention having a sentimental side, meaning they can be emotional or nostalgic. Over time, however, the stress and demands of their job have weighed on them. Think of a nurse who loves helping patients and takes pride in their work, but after many years, the long hours and difficult situations start to drain their spirit. The 'heaviness to their soul' means they feel emotionally tired due to the nonstop challenges of their profession. This shows that while dedication is admirable, it's important to also take care of one's emotional well-being. If someone feels this way, they might need to find ways to balance their work with activities that relax and rejuvenate them, like spending time with loved ones or pursuing hobbies they enjoy. This helps prevent burnout and keeps them feeling fulfilled both personally and professionally.