short answer: yes I think it is a bit long.
What I like about your cover letter is that it is very structured. However, not all points are equally relevant. Try to focus on the most important ones. Try to simplify the language to make it an easy read. Try to also think from the recruiter point of view. This is a cover letter and not a CV, i.e. list your skills, abilities, value to the company and do not put your past experience & achievements in the focus -> instead use your past as evidence for the value that you can bring in the future. This is a small but very important difference!
Furthermore, you need to improve the formatting. Either you consistently bold important aspects or you don't, but don't mix the style between paragraphs.
Please let me know if you have further questions or need a more detailed revision.