Let's start with being open and honest with your partner(s) about what you're looking for in this relationship. For example, if you're absolutely certain that you're ready to have sex with this person then the both/all of you should get tested to make sure you're being safe. That might seem like a pain to do, considering how long it takes for the test results to come in versus how active your libido might be, but it would create a safe space for everyone.
Communication is a huge thing, as I've mentioned before. Sexual energy is a powerful thing to experience, but it would be hard to hold that and keep in mind anything you've experienced in the past. For example, if you have endured sexual assault or rape, you may have difficulties trusting someone enough to have sex again. A kiss or caress could make you severely uncomfortable. This does not make you weak or a coward. You're amazing for loving again! It is understandable and your partner(s) should be supportive in your endeavors. You deserve to have a healthy sex life, if you want one. This does mean you should work with your partner to make it safe for you and them. Perhaps starting with trust exercises to build intimacy and talking about sex might be a good start.
Survivors of PTSD may have a completely different outlook on sex. Instead of anxiety, those with PTSD tend to be less interested in sex. They also tend to become numb to most emotions, indifferent to anything that might take them out of their numbness. This is because staying numb is synonymous
with safety to them. Male-identified survivors may also experience erectile dysfunction and premature ejaculation. Experts suggest treating the PTSD in order to increase sexual interest.
Here are some ways you can make a comfortable environment for yourself and your partners(s):
Being clear: One can say "no", "I'm not interested", "I'm don't like this" or other words to indicate they're not ready or having a good experience.
Patience: It's easy to get caught up in the moment, but taking it slow can also be sexy. It is also important when you're with someone who has dealt with sexual assault. Re-traumatization could occur when the survivor is triggered by sexual acts.
Talking it out: Maybe you or your partner(s) aren't ready for sex. This is totally okay! Sure, one might feel guilty for not wanting to have sex but it would be beneficial to enjoy sex at a time when you're ready.
Please let me know if there is anything you feel is missing, if I got something wrong, or if you'd like me to change something. I am not a trauma survivor, but I am an ally.
Here are some links for light reading!