So far, i have been very fortunate that i have enjoyed whatever trade/biz i have been in. To make it short, i grew up loving farm work with animals. Went to college to study agriculture (dairy farming and animal husbandry). during my sophomore year, it suddenly dawned on me that i was working my way thru school by working in construction. I quit school and built a kitchen addition for my mom and as soon as that was finished, i took 2 yr vacation with Uncle Sam, came home and started my own biz. I was going to be a carpenter, but first job was as mason to build stone steps. Second job>>> another masonry job. Third job >>> another masonry job. I was stuck and loved it. 30+ years later, my back was gone and I had shrunk from being 7 feet tall to bumping my kneecaps with my chin. I took stock again and got into landscaping. Even tho my (formal) education education had not been with growing bushes and trees, i built up a library of info. I was off and running. When i realized my body was no longer able to do any more (real) heavy work, i got more into lawn care only. I am still going strong at that at an age of 39 (which of course, I have been 39 for a lot more years than i wasn't)
i have been fortunate to have been able to change directions to do things i really enjoyed. I have, with every change, bought books and more books, both hard cover and soft cover to take as much advantage of other's learning as possible. A lot of hob-knobbing with others who know more than i. Not afraid to struggle to get started with anything. If the books are not affordable for purchase, libraries are available in nearly every town.
About the not finishing on time problem, you do the best you can. nothing to be ashamed of. The next time is always better so you keep plugging.
Tinker