My apologies; I didn't see this until just now.

When I mention your relatively lower reading skills, what is most striking is the gap between verbal cognition (extremely high) and assessed comprehension (average); it's not actually below average, so some psychs would not consider that SLD (in the DSM-5, the criteria have led to some controversy about whether ability/achievement discrepancies alone can constitute an SLD if the level of achievement is at least average; in your case, the SLD Dx would require the use of ability/achievement discrepancies, as you do not display below average reading achievement, with one exception). Your reading speed is actually below average on the Nelson Denny, which, if reflective of your typical reading pace, would suggest that your reading efficiency is far below that predicted by either your verbal cognition or your visual-motor processing speed.

It is possible that inefficiencies in reading speed and comprehension are related to dysregulated attention, rather than an underlying reading disability, but it's generally worth asking the question. When the cause is attentional, what generally happens is that the reader reads slowly because of losing track, or because of backing up and re-reading due to having trouble maintaining continuity. Comprehension weaknesses are related to how fluctuating attention interferes with making cause and effect connections across lengthier text selections.

In your case, I suspect that some of your struggles in college reading were related to a) slow reading speed (of whatever cause), and b) the gap between your concrete and abstract verbal abilities, which means that you are much better at soaking up facts than at generating interpretations. This might look like feeling as if you understood what you read, but then struggling to explain, integrate, and extend meaning from literature selections. Because repeating back facts is easier for you than articulating the higher-level concepts, it will probably be important for you to learn and use some specific active reading strategies, especially those that involve narration (restating/retelling in your own words). You might want to take a look at some of these. I like SQ3R:
verbal description: https://www.nhti.edu/student-resour...-solutions-lab/reading-and-learning-sq3r
bullet point pdf: https://www.weber.edu/wsuimages/vetsupwardbound/StudySkills/SQ3Rmethod.pdf
video:

video w/more visuals:

But you can also google "active reading strategies" for other methods. You might, in the past, also have been dealing with factors interfering with your focus on extended reading selections, the details depending on what mental health issues were in play (e.g., people with thought disorders, like schizoaffective disorders, or with anxiety disorders, like GAD or OCD, often struggle with intrusive thoughts, which can make it quite challenging to sustain continuous concentration for a long or complex reading passage).

Your ADD rating scale suggests mild to moderate vulnerabilities in activation, and significant concerns with affect. It does not, however, suggest dysregulated attention, poor motivation, or working memory deficits, which is likely why you have encountered professionals who disagree with the ADHD diagnosis. The indirect measures are consistent with the direct measures, that also found your attention to be at least average, and your working memory to be high average/above average. The at-risk score in task initiation does suggest some kind of executive dysfunction, while the clinically significant affect score doesn't specify the source; these symptoms could arise from other conditions, including mood disorders, or specific (temporary or environmental) stressful circumstances. I would not be surprised if the executive dysfunctions are indeed related to the mental health history you report, as that is not unusual.

To return to your original key question of your likely success on a return to post-secondary education: What you've reported and described appears to be a learning profile that is capable of success in college coursework, as long as you surround yourself with supportive structures, routines, and persons for managing your mental health and task organization (cloud-based calendar/reminder systems will become your best friends, if they aren't already--GoogleCalendar, GoogleClassroom, etc.). If you choose to take courses, make sure you have a good conversation with your college's disability services, especially campus mental health providers, regarding accommodations (consider extra time, separate test setting, course notes provided/lecture notes) and tutoring supports.

...pronounced like the long vowel and first letter of the alphabet...