WooHoo! Congrats on your ST TTC Mako

Hi MissMagpie and congratulations on your little man! I second the recommendation to visit the breastfeeding problems & support area.
If he's a lazy feeder the best thing is probably practice. You could try taking him off the breast after 20 mins or so. Burp him and give him the other side. Switching him back and forth like that might get more milk into him quicker.
For what it's worth, A also fed for a very loooong time when he was that age. He gradually got faster. then around 3.5 months he suddenly got very fast (i mean it was like an overnight change) and would only take 2-3 minutes to feed. It's quite normal for babies to want the breast all the time when they're little if they feel tired or uncomfortable or whatever. It can be quite trying for mums, though, so hope you're getting plenty of help and support.