I had the same problem a few months back getting the same mediocre results when using store brand products or even stuff from health stores that had all natural ingredients. I'm also at university so it was getting very very frustrating!!
I bought the science of black hair book just to see if I really was on the right track in terms of understanding my hair. Anywho, in the products section there were different recommendations for hair products.
The key thing I took away from that section was to stick to one brand of hair care products (if u could)that balanced your moisture and protein well.
So I bought the elucence brand and my hair has been amazing since then.
The moisture conditioner by that brand is THE best conditioner I've ever used for my hair. The protein conditioner is even better!! I have 4b more 4c type curls (or non-curls), so moisture was defo needed. I also realised that my hair responded better to the first sets on ingredients being an infusion rather than just the bog standard 'water, cetly alcohol..." Etc. I didn't realise this untill I used hello hydration and Avalon where my hair felt yucky for that week Lool.

One question to also ask: how would you describe your porosity?

Another thing I've started to do now is to mix my moisture conditioner with acv or if I do a protein dc ill mix it up again.
my hair is more sheeny, bouncy, defined and healthier looking.
I can attest that to both the change in conditioner, getting my balance right and chucking acv into the mix.