I need help to set up SPF, DKIM & DMARC

Hi friends. I need help to set up SPF, DKIM & DMARC. Hopefully someone can help out, because I am a bit lost. The first problem I'm having is the SPF.

Background.
We have had a lot of trouble with emails being sent to spam over many years and I always thought it was because we send a newsletter and eblasts regularly (send too many emails) and there was not much we could do about it.

But now, after what appears to be many months, I discovered our IP and all emails from the server have been blocked.

So these problems brought me to an area I don't know much about, namely setting up of SPF, DKIM & DMARC. I have already spent many hours going thru the tutorials but the configuration of the SPF script has got me baffled.

Could someone possibly help with the SPF configuration?

Our email delivery situation is like this.

We use gmail to send our @thebeatbali.com emails.

I checked our SPF situation on Google https://toolbox.googleapps.com and it returned this.

SPF must allow Google servers to send mail on behalf of your domain.

Decision SPF fail - not authorized
Record v=spf1 +a +mx -all +a:beatmag.com

DMARC is not set up.

No Google mail exchangers found. Relayhost configuration?

If you intentionally set up a mail server somewhere on your premises that automatically forwards all incoming mail to Google you may disregard this warning. Otherwise - this is a serious configuration error as it causes disruption of mail flow.
10 mail.thebeatbali.com

Everything else was ok on that test.

Google says if you only use gmail workspace the SPF should look like this.

v=spf1 include:_spf.google.com ~all

This is where I get lost.

Important.
We also send bulk emails and newsletters from our server using Mailster. So those emails go direct from thebeatbali.com server.

So how does the SPF look when using Gmail SMTP service and Mailster?

At present the existing SPF looks like this.

v=spf1 +a +mx -all +a:beatmag.com
(beatmag.com was a previous name. We now use @thebeatbali.com for emails)

So this is my question.
Does a Google reference have to be included in the SPF? Or do all emails go thru the server thebeatbali.com in regard to the SPF?

Thank you