I've had ankle issues for a while and I've also been broke. The only real solution without paying for physical therapy and/or surgery is to get a strong ankle brace. Get a strong one that you lace up.
This is the one I use and it's very effective. You'll have to get used to the bulk of it at first but you'll adjust quickly.
Absolutely do exercises to strengthen your ankles. However, if you do need braces, you can find them at most sports stores or online.
I don't see any damage to any of the bones or dislocations of any kind or any other kind of injury that would be visible on an X-ray. So, it sounds like you have a soft tissue injury. That could mean anything from a sprain to a pulled or torn ligament or tendon. Most likely, it is just a sprain if you didn't have an incident that you remember causing the injury because the force needed to tear a ligament or tendon is usually strong enough that you would know what did it.
The treatment for a soft tissue injury that does not require surgery (which, by the sounds of it, yours almost certainly doesn't...but, if it doesn't start to improve or gets worse after doing these things for at least 2 weeks, I would go back to see a doctor and ask for an MRI to make sure your ligaments and tendons are not in bad shape) is RICE at first which stands for Rest, Ice, Compression, and Elevation.
So, for REST, depending on the severity of the injury, for the first 2-8 weeks, you need to completely rest the ankle as in not trying to move it at all and using crutches to get around so that you don't put weight on it. You should be able to get a pair from your local pharmacy. At least you can here in the US, I don't know about where you are. If you can't, you can at least order them on Amazon for a pretty reasonable price. Or you can go back to the doctor and request crutches because you are having so much difficulty walking still.
Next step, you want to ICE your ankle every day for the first 2 weeks in intervals of 15 minutes on with 15-30 minutes off. Do not exceed 15 minutes on because you can damage your skin with the ice that way. Also, always use a towel or some kind of barrier between the ice and your skin for the exact same reason. After 2 weeks, you can alternate between using ice and heat (a hot water bottle or a heating pad works great) using the same 15 minute intervals except you can go back and forth between 15 minutes of ice and 15 minutes of heat if you like or you can take a break between them if you prefer. By doing the alternating, you actually help reduce inflammation, loosen tight muscles, and stimulate healing.
Then, for COMPRESSION, you want to invest in either an ace bandage and wrap it in a figure 8 style to give a stable support to your ankle or, even better, an ankle brace designed specifically for stabilising the ankle such as a lace up one with plastic or metal stays/supports on the sides which you should also be able to get at your local pharmacy or on Amazon.
And finally for ELEVATION, as often as possible, you want to prop your foot up and keep it at or above hip level when sitting upright but, ideally, you want to keep it above the level of your heart as often as you can. So if you are in college, put it up in an extra chairs in class (I'd bring a throw pillow with you to put in the chair to rest your foot/ankle on for comfort). If you work a desk job, do the same thing. If you are at home and have a recliner, try to keep it leaned back and use a couple of pillows to prop your whole leg up. If you have a sofa instead, use some pillows to prop your back up if you like/need but, more importantly, use a couple of pillows to elevate your whole leg up. And, when you are in bed sleeping, you DEFINITELY want to prop your leg up on pillows since that is the best time to let it be elevated for an extended period of time.
Then, after about 2-4 weeks (you'll know when it is time to move on from RICE because you will have significantly less pain and the visible inflammation will have gone down), you will switch over from RICE to MICE. So, instead of REST, you will switch to MOVEMENT. At this point you can start doing gentle movement such as circles, pointing, flexing, etc. Then you can progress to gentle strength exercises using resistance bands and such. Once you progress to MICE, you can decide if you feel like your ankle feels strong enough and pain free enough to go without the crutches. You may need them the full 6-8 weeks.
In addition to this, you should continue with the ICE, COMPRESSION, and ELEVATION. You may be able to stop the ICE and ELEVATION after 6-8 weeks but the COMPRESSION may need to be continued longer depending on how stable or unstable your ankle feels at that point. It will be up for you to decide.