It makes sense that the bank is dividing it by 5. They can only take the amount that you have earned in the last year and divide it by the number of months. Also, you are probably lucky that with short term leases they are even coutning the income. Short term (vacationa type) rentals are very seasonal and most people would assume that the income in the summer would way outstrip income the rest of the year (unless in a ski area and then it would reverse to winter) I think you will be SOL until both properties have a full year of tax retunrs available on them. The banks are going to be concerened that you are in over your head too much too quick. For example, with 3 properties, you need reserves for repairs, etc for all 3 (probably 25K plus)
Last, the wise move would be to take the 3K+ per month according to your figures, you are making in income off the 3 properties and pay down the debts over the next year. Than maybe you could refi or get the payments to a better DTI range for loan approval. Also, by then you will have the extra qualifying income. Honestly, even if you found a lona package right now, it would be an ugly one cost wise due to the market for investment properties and the high DTI. It is not like the prices are likely to jump alot in the next 6 months, and even if they do, at least you will be buying with alot better footing to do so.