@Sarah Enero - it's a good dilemma to have - you have options! That said, are you expecting to cash flow $2000 a month or a year off the STR? What city are you looking at for a STR? Keep in mind that 2nd home loans are going to have a hefty fee added to them starting April 1st of this year. Please view this article I wrote about the new fee here: https://emilybernardo.exprealt... No one has a crystal ball to know what housing prices are going to do here in San Diego over the next 5 years, but I think it's safe to say that interest rates are going to go up. That could make getting a HELOC risky and if the market softens of the next 5 years and you buy now at the top, you aren't going to have any equity to take out.
IMO, instead of the STR option, I would look at investing into a turn key rental in a less expensive and more stable market. The mid-west (ex. Ohio) has stable rental markets w/o the huge price fluctuations we have here on the west cost. You can cash flow a couple hundred a month and have a property management team that will take the hassle out of being a landlord. Plus, you will get all the tax benefits of owning real estate.
Cash flowing in San Diego is a long term proposition unless you have a lot of capital upfront to force equity through adding an ADU or doing a rehab. If you aren't opposed to having a roommate, you could look for a 2 bedroom here and rent out a room to help cover your mortgage. You can even rent rooms out to travel nurses - they are gone all the time and usually take assignments from 30-90 days.