@kmar123 A few thoughts.
Your boyfriend is correct that working out outside when it’s cold and you’re not used to it can be an intense adjustment. This is both for your breathing (taking in a lot of cold air) and your muscles and skin. So definitely working out in 10C if you’re used to working out in a much warmer environment can be part of what you experienced. Nothing to do but get used to it, unfortunately, although wearing warmer clothes can also help.
Running is high impact and repetitive. The shoes you wear
matter. New runners shouldn’t necessarily go out and buy a super expensive pair of shoes, but if you’re using really old shoes, or shoes that don’t really work for your stride, they might not be doing you any favors. If you think the knee problems might stem from your shoes, see if you can visit a running store and get something reasonably priced for your feet and stride.
Are you using a marathon training program that recommends interval training? Marathon training for beginners is usually more focused on sustained runs, since that’s what you’re going to be doing in the actual race and you probably don’t care about setting a specific time. I would expect a marathon training program for a beginner to recommend something like a 30 minute jog supplemented by walking as needed as its first day, not a 30 minute interval. If you’re not using a training program, definitely find a few for beginners, read what they recommend, and choose one that appeals to you.