If you get your mindset right, you can dictate the combat even in an inferior plane, and with somebody on your 6.
First of all.. you're in a slower plane.
This generally means you can turn better - So you use this to your advantage.
The ME109 is coming from 'advantage' so you need to reduce this advantage.
You 'bait' him/her/AI by going into a gentle turn but keeping an eye on your attacker.
You turn in such a way that the deflection is just too much for the attacker to get a lead shot on you. By doing this you keep your speed up and bleed their speed.
If the attacker suddenly pulls extra lead to get a deflection shot, you just roll about 30 degrees and carry on turning - they'll miss by a mile, and they'll bleed more speed.
Now's the big point:
Practise rolling your a/c at max roll rate... the best way to do this is put the aircraft into a psuedo controllable stall condition. It bleeds speed but it will whip you around so fast onto his tail (any aircraft can do this) into a firing position as he/she/AI (I'm not desciminating against the AI

) passes. You usually have only 1 second window to get a good shot.
A human will cra,p themselves and give up after a few go's, but maybe an AI will be dumb as usual and suck in your shells.
There you go.. simple isn't it...