I had tennis elbow in both elbows at the same time. It was hell. I was trying to grow my forearms by working them a bunch and it was a terrible idea, lol.
Few things that really help.
1. Keep working the forearm, little at a time doing wrist curls/reverse wrist curls. Start light, something like a small can of soup, few sets a day, stay at this weight until reps can be completed without pain and then move the weight up a little. Continue doing this until full strength is regained.
2. Deep tissue massages. I didn't personally have art done but I've read about it and it is very expensive, only preformed by a license trained chiropractor. Will leave bruises and supposed to be very painful but results are also supposed to be amazing. I would massage my forearms by straighten my arm down by my side, make a fist and roll my my hand inward, stretching the outer forearm and pin a large foam roller between me and the wall and roll my forearms out for as long as I could endure. When you release the stretch, you'll feel the blood rush into your muscles, feels great.
3. Wear tennis elbow strap. They help, apply pressure on the forearm muscle and helps alleviate pain. Also, supporting your wrists. Wrist movement activates the forearm muscle aggravating tennis elbow. Wrist braces to help stabilize wrist can help take stress off muscle. I also wore compression sleeves.
4. Topical creams. I like penetrex, it's a topical anti inflammatory. It's a little pricey but highly reviewed product. Doesn't burn and isn't stinky like bengay. Nsaids can prolong tendon healing. I try to avoid ibuprofen, etc.
One other product that is highly recommended but I've never used. Theraband flexbar. I would look into this product.
https://www.amazon.com/dp/B000KGOMBC/ref=cm_sw_r_cp_apa_fabc_9c57FbB6X9MR4