.com to a .co.uk?

I'm out ranked by people with FAR less links for Google in the UK and I think its purely down to the fact I'm using a .com rather than a .co.uk.

I'm based in the UK but there's other aspects of my business that I want to target internationally although my main hub needs to be UK.

I set my geo-targeting and it didn't help.

Tried doing mydomain.com/mainkeyword-uk. Its picked up on this and I'm in top 10....but would obviously prefer number 1.

Worried about doing a 301 redirect from .com to .co.uk because of loosing even a little bit of link juice. I've already put so much effort into the .com.

I get so many different answers to this.....some people say switch to the .co.uk and others just say keep the .com.

If I keep the .com and link build to mydomain.com/mainkeyword-uk as well as build page authority for overall site......would that be fine or will I just absolutely have no chance in heck with ranking competitively in the UK if I don't do the .co.uk?

Trying to pick the path of least resistance and best possible returns here.

Not a pro...just a small business owner trying to teach herself SEO....so be gentle with me. x