If you're good at math, which is hopefully the case if you're studying aerospace engineering, then tutoring 6th form and GCSE kids can be a good part time job. The rates are normally much better than most student-friendly jobs and can likely fit around any weekend work you might do. Include the fact you're studying aerospace engineering and the university you're at in your ad offering tuition services. And/or reach out to friends, family and friends of the family to see if anyone's kids need tuition.
My experience in London is about a decade old, but when I was at uni there flat hunting was like going through the 5 stages of grief. I doubt much has changed. You uni housing office will likely have listing from land lords who rent to students on a 9 month basis, as well as a list of landlords to avoid. This is something you'll all need to sort out ASAP. If at all possible try to get separate rent agreements, which a lot of landlords who rent to students are generally able to work out (or were when I was a student in London). I know this isn't much help for the more immediate time frame but getting this sorted now, before all the cheap and close places are taken for next year, will save you a lot of time and money.
Do you have career relevant summer work lined up? If not then it's likely too late now but still apply at every company that might be suitable. Send in speculative applications if they don't list anything -worst case it goes in the trash. Summer gigs with engineering companies can often be turned into sponsorship deals where they give you cash each year (in addition to normally paid work in the summer) if you promise to work for them for a bit after you graduate. Providing you make it through this year your number 1 priority should be applying for these positions, as early as possible. Note any companies that have very formal application processes and closing dates and be ready next year the day those applications open.
What is your feeling about the armed forces? The Army, Navy and Air Force all do sponsorship and bursary deals that can be worth around 8000 quid a year (amounts vary between the three), but they require you commit to some number of years in service (you start at officer level). If you want to go into aerospace a military background of some sort will almost certainly be beneficial. For a much lower level of commitment there is the OTC, which is essentially a recruitment tool where you get paid to go camping or do other army training a couple of times a month - no commitment to serve and you can't be called up and sent off to war - it will also be decent on a lot of aerospace CVs, assuming you're planning on going into that field.
(Went through a similar experience as you in London in my second year, it blows. Good luck)