You are going to want to look up "bho winterization", which involves using anhydrous ethanol, cold temperatures, and filtration to remove more plant matter. The basic process involves dissolving the BHO into ethanol, then bringing the temperature of the solution down as low as possible(dry ice+ethanol or cryo is ideal, home freezer will work). As the temperature drops, the fats and lipids will start to solidify and fall out of solution, and they can then be filtered out. You will then purge the solution of the ethanol in the same manner you would purge butane(keeping similar safety protocols in mind, namely VENTILLATION).
This can be done with cookware likely found at home, like glass cups, coffee filters, and rubber bands. The process is made much easier with simple lab tools like a buchnuer funnel.
While you have the bho dissolved in the ethanol, you can also perform what is called "color remediation", which is a process that uses absorbent materials to remove the pigments from the solvent, leaving a very clear final product. This is often referred to as "CRC tek" or "Color Remediation Column Tek". This step is a little more complex and might be difficult to do at home on a budget.
You could potentially skip this step, depending on your end goal, by just getting your material and solvent cold enough during extraction so it won't pull lipids as well.
The meth like crystals you mention is likely THCA crystals. Due to the molecular properties of THCA, it tends to crystalize when in high enough purity. This is one of the reasons why its decarboxylated isomers, d8 and d9 THC, is used in vapes as it tends to behave as a highly viscous oil, especially when diluted with terpenes or other cutting agents.