Stuck in Dilemma on how to grow

Greetings everyone!

I am an investor who has grown a small portfolio and am stuck on what options to consider to grow.

I live in Houston.

I have 3 homes currently:

1. Personal Residence ($210k balance at 3% for 15 year) Appraisal Value $400k

2. Rental One ($100k balance at 3% for 15 years) AV $210k

3. Rental Two ($145k balance at 4.5% for 30 years) AV $200k

As you can see I have aggressively paid down my personal home over the 4 years.

I don't know how to add a 3rd rental as most lenders tell me that my debt to income is high.

I have enough saving that I can pay off extra $24k every year but trying to figure should I pay off the lowest balance 1st and then finance a 3rd property after 4 years. Or save the $100k and buy a smaller home in cash.

Basically am stuck on how to grow my portfolio? Any guidance would be appreciated.