if you are the sole owner of the landscaping business and it is not incorporated, it gets reported on schedule C.
your return is not late since you extended it. it is now due 10/15/2019. however, if there is a balance due the IRS will bill you for late payment penalties and interest.
in one place you say you left your old job in 2017 but another you say you left casino in 2018. which is it?
did you get a 1099-R from your employer which included in the taxable amount the loan. the reason I ask is there was a change in the tax laws for 2018 regarding 401(k) loans. here it is
Effective January 1, 2018. Section 13613(a) of the law, cryptically titled “Extended Rollover Period for Plan Loan Offset Amounts,” now gives you potentially until October 15 of the following year to offset the outstanding 401k loan balance and avoid taxes and penalties.
Example: You owe $25,000 on a 401k loan when you’re laid off on November 20, 2017. you don't repay the loan within the period required by your plan and elect to rollover the balance into an IRA which the employer does in 2018. 8 taxes. Now, you may have until October 15, 2019 (the tax filing date for 2018 plus a six-month extension) to roll over the $25,000 to an IRA or new employer’s plan to avoid the tax hit. You can use that additional time to get back on your feet and avoid the taxes and penalties from a defaulted 401k loan.
Section 1.402(c)-2, Q&A-9(b), provides that a distribution of a plan loan
offset amount is a distribution that occurs when, under the plan terms the participant’s accrued benefit is reduced (offset) in order to repay the loan. if the Plan so provides , this can occur in the event of an employee’s termination of employment and the loan is to be repaid immediately or treated as in default.
Any portion of a qualified plan loan offset amount may be rolled over into an eligible retirement plan by the individual’s tax filing due date (including extensions) for the taxable year in which the offset occurs.
so if the offset occurred in 2018, you have until 10/15/19, to put the 50K into an eligible retirement account and thus avoid all taxes and early withdrawal penalties
failure to do this will subject the loan to income taxes and if you are under 59 1/2 early withdrawal penalty of 10% for 2018
if taxable the loan amount would be reported on the same line as the 1099-R 4a and 4b of 1040. the 10% penalty through form 5329
