We have 24 hours in a day. If you take out 8 of sleep, assuming you're wise enough to sleep properly, that leaves 16 hours in a day. A regular job is 8 hours on weekdays. That leaves you with 8 more hours.
Without counting transport and meals, what do you do with those hours?
If it takes you more than 30 minutes to get to work, maybe you need to find a closer job or move closer to it. Meal prep can be done on days off. Bulk cook and freeze. Take your meals for the day out the night/afternoon before. That saves you a considerable amount of time.
Do you have family? I guess not, since you didn't mention it. You just mentioned full-time job as an obstacle.
What do you do the rest of the day? Do you spend it gaming/watching tv? Cut on that. You don't need 6-8 hours of it every day. Nobody does. Max 1 hour is fine. And another 1 hour you can dedicate to take care of your body, which is also super important. If you're a man, you should do 4-5 times a week to keep your energy flowing properly and increase testosterone levels.
You still have time to work on personal development, meditation, and JoS after those.
It's usually time mismanagement that makes people think they don't have time. Their dopamine processes are impaired, so they think they need constant stimulation from popular modern forms of entertainment, and they equate those with "living life to the fullest" when in truth overdosing on entertainment is "wasting life to the fullest". Everything in moderation.
After someone fixes their dopamine addiction and embraces discomfort which is even more essential for men than women, they can explore and discovered how much entertainment they actually need in a day/week. And this varies by person but an impaired brain will always overestimate it.
Some people also have variable levels. They may function with none, than need double the day after. Average it weekly. Other people may find that entertainment and productivity often overlaps. Some people for example would put physical training in productivity. For me and other people I know, it's both that and leisure. Some people will think meditation is a chore, others enjoy it very much.
And you change as you grow into a better version of yourself, if you allow yourself to grow.