I hate to say this but applying for a loan on bank for the purpose of buying Bitcoin is a bad and very risky idea. I just don’t know what are the terms that you have with the bank in paying back the loan, but it would be much worse if either BTC would go down even further and tread water for a long time.

There are no promises or guarantees if BTC can give you 100% to 500% profit in 2 years as you said. I just don’t know how confident are you in this, but I am sorry loaning for the purpose of buying 1 Bitcoin is not a good idea at all. If I were in your shoes, I wouldn’t do it and just only invest an amount that I can afford to lose no matter what. By the looks of it in your financial status, I don’t think you are ready to afford losing $20k. Unless you are making $20k a month, for sure you can afford.