I know it sounds scary but if you want to have a career in forensic psychology, for example, you must go to university.
The best way to take the "scare" factor out of these types of decisions is to thoroughly research the "risks versus the rewards" and if you determine the risks are worth the reward, then you mitigate as many risks as possible, as low as possible.
So, if you are currently working 3 part-time jobs to make ends meet, then the biggest risk I think that comes to mind is the inability to pay for your living and school, and have enough time available to devote to your studies to ensure that you do well. Doing poorly in school will not help you advance in a career that places a high level of importance on your grades.
So, if after researching your career prospects to determine that the rewards outweigh the risks, then for this particular risk, you will want to find ways to pay for school and expenses so that you do not have to work so much. Preferably any type of grant or scholarship that does not require you pay it back is better than accumulating debt.
Start with the companies you currently work for. Maybe one or more of them offer scholarships, or tuition reimbursement if you continue to work part-time. Then, if they do, consider dropping the other jobs, and find supplemental grants and scholarships to help with the costs.
As a last resort, look into financial aid that must be paid back upon graduation. Again, you must consider the debt to payoff ratio. You would be ill-advised, for example, to accumulate tens of thousands in debt for a career that would take you 40 years, due to the salary, to pay off.