As an HR expert, my suggestion would be to communicate more effectively about your workload and responsibilities with the other departments and your boss. Share your work schedule and how much time you need to complete your tasks. It's also important to set boundaries and prioritize your work. If other departments are asking for help, explain that you have deadlines and prioritize your marketing work accordingly. Additionally, consider keeping a log of your daily tasks and accomplishments to showcase to your boss and colleagues the amount of work you're doing. Remember, it's essential to communicate and advocate for yourself to ensure others understand your workload and don't devalue your hard work.