As a lender we would require that you have two full years of working both jobs before we could count they second job income. The reason behind this is to prevent people from doing that very thing, obtaining a second job to lower their debt to income ratio to qualify for a home loan. Also it takes stamina to maintain two jobs but after two years of working both it would show that you could maintain both.
It sounds like you have worked off and on with the second job which is helpful and we would use that as a compensating factor to help make the loan stronger but still would not be able to use the income.
Also, lenders do look at second jobs differently and you might find one that would allow some of the income from the second job under certain circumstances.
Another option might to obtain the second job and use the additional income to pay off a loan that isnâ€™t revolving; this would help lower the DTI for you. Some lenders will allow for you to pay off a revolving account IF you also close the account. I would double check with your lender though before paying down or off any debt as they will know their particular guidelines.