Generally speaking,in terms of actually practising as a commercial solicitor, contract law is much, much important than trusts for the vast majority of the work unless you're in a couple of niche areas.
The other thing I'd say is to try and give the trusts stuff a bit of time to sink in - as a student it feels a bit strange and detached compared to more easy to visualise topics like contract and criminal etc.. but give it time and it will make more sense!
I found equity and trusts a hard to understand topic on my GDL, a number of years later as a solicitor I ended up working on some complex corporate trust structures for about 18 months and it all clicked in a way it never did as a student - so keep at it!
Check what the contents of the commercial law module are, but I'd expect it to be much closer to contract than trusts.