Venting is good! I was in your shoes 4 years ago, wondering how I would ever develop proficiency in getting everything done each shift. It has been a long journey, taking 1 day at a time (sometimes 1 minute at a time). There are good days and bad days (sometimes good weeks & bad weeks). It took at least 3 months for me to no longer feel like a fumbling idiot then another 3 months before I had any sense of proficiency. At the 1 year mark, I sighed, relieved that I believed I could handle it. Now, I still have times of exasperation alternating with proficiency.
Find good support "mentor" nurses. I went to mine a lot for the first 3 months. Mine weren't assigned by the facility, I sought out those experienced nurses that I respected who were willing to nurture (not eat) their young. They knew I was a willing learner, hard worker and able to do the job. They also knew I needed lots of guidance.
Watch other nurses, ask them questions, ask for suggestions, observe "tricks of the trade" that work. You will eventually develop a plan that works for you.
Give yourself time. You sound like a wonderful conscientious nurse. It does get better!