How to avoid "Process running mem=544M(100.3%)" on Heroku with Selenium

I am trying to develop an application that needs to do web scraping. It is a complex scraping so I need a powerful tool such as Selenium.

The problem I have is that after few calls I start having errors:

Process running mem=544M(100.3%)

What I tried at the moment:

1. setting start and max memory of JVM to 64m! (yes I don't need to much memory for my app, but did nothing). This option remained active also with the following attempts.
2. creating and quitting WebDriver (Chrome) at every usage: it seems to work, but it is basically useless because it needs 2 seconds just to retrieve one instance (poor solution)
3. pooling some instances in async just to avoid those 2 seconds: after 3 instances application is unable to create new instance with errors such as missing file blah blah blah... and anyway because of the scraping I need to do a lot of things everytime that I could avoid if I could use the same WebDriver more than once
4. creating a wrapper of WebDriver that quit and recreate the wrapped one after a number of usages: after 20 mins the errors appeared again

I am wondering if there is a solution that is alternative to 2.
I read a lot of answers saying that you need to quit/close, but I have just one window open and reusing it would be more effective than creating a new instance everytime I have to do something... Do you have any suggestion?

Tech data:

• Java 11
• Selenium 3.141.59
• Heroku free tier